Wheeler 12/09

Ah, Friday the ninth of December! A very very cold day. A day that really made me miss my home in North Carolina, where a couple inches of snow was the most I ever saw each winter. I remember I never liked having much snow. But now that I'm here, in unpredictable Ohio, I prefer the couple inches over a couple feet. Anyways, on to Physics now. Well, really, I'm sure we could find the final velocity of falling snowflakes by applying our formulas, maybe having to call up the weather man to help us out with the initial velocity. We already know the acceleration due to gravity is 9.8 m/s squared. If the snowflake wouldnt melt before we weighed it, we could find its mass on our own...I should stop now before I give Coats-Haan any ideas. But really, I am moving on to Physics class now.

Well, I really hope this is not a surprise to any of you, and I am rather scared for you if it is (unless, of course, if you are Chris Roseblossom, my lab partner, who is just really too smart for his own good), we took a test over Newton's Law Application. I studied using my Newton's Law Application Test Review, which we turned in on Friday. The answers were on the physics website, and Coats-Haan even showed her work for us, like usual. The test reviews are always helpful for tests and also exams, so I save every one of them. Psst! You should save them too! They make filling out the quarterly exams a breeze!

QOD: What do you know about astronomy? About the only thing I know about astronomy is that it involves the study of the stars. However, I'm sure there is some in-depth physics reasoning behind astronomy that we are about to delve into on Monday.

12/9 qod

What do you know about astronomy?

--ch

12/8 Scheitlin

If you missed today you really didn't miss much. First off we turned in our pair check from yesterday if we hadn't already and then checked our homework from last night (centripetal force worksheet) and asked questions. Then we had the rest of the class to work on our Newton's Law Application test review which is due Friday (our only homework besides studying and the lab report due next week) and ask Coats-Haan any remaining questions we have. We also found out today that Coats-Haan has an inferiority complex to Kreider and (her words not mine) she has never beaten him at anything except that her shoes match her shirt.

Question of the Day:  We only learned one new equation this entire unit.  What is it?  Why was there nothing else that was new?            
 Well I am really confused because I thought the fun equation and the center of mass definition equation were new but I am assuming that one of them is just a rearrangement of a previous one. However, I cannot figure out which one we have had before.                              

12/8 qod

We only learned one new equation this entire unit.  What is it?  Why was there nothing else that was new?

--ch

12/7 Tamayo

Today in Physics we received quite a bit of items in our folders. We got back our Newton’s Laws test, our Lab Report which was turned in on Tuesday, Our Center of Mass Pair Check, and our Center of Mass Reading Question sheet. We did not turn in anything in class today. Today we compared our homework which was questions out of the book with the key while Coats-Haan checked them for completion. After the homework we took notes on Uniform Circular Motion, which dealt with centripetal forces.  During these notes Coats-Haan pulled out the Japanese anime doll on a string to illustrate the concepts of today’s lesson. This is the second appearance that the doll has made in Physics this year. We revisited the equation for centripetal acceleration which is a=v²/r. r is the radius and v is the velocity, and a is acceleration. We learned to apply Newton’s Second Law ∑f=ma=mv²/r as centripetal force f is directed radially inward. We then proceeded to complete problems 10 and 11 in the example packet. We then completed a pair check. It was helpful to complete the pair check problems out of order because the second to last problem proved to be the most difficult. Our homework was to complete the centripetal force worksheet, which consists of an explanation of the problems and five problems to be completed.

Work turned in. None (checked Homework)

Work assigned. Centripetal Force Worksheet Due Thursday, Newton’s Laws Applications Test Review due Friday.

QOD. What are some forces that can act as centripetal forces? What is the direction of a centripetal force?

Three forces that can act as centripetal forces are gravity – a satellite orbiting earth, Tension – twirling an object on a string, and Friction – a car travelling on a circular ramp.

The direction of the centripetal force is directed radially inward.

12/7 qod

What are some forces that can act as centripetal forces?

What is the direction of a centripetal force?

--ch

12/6 qod

Why is it impossible to touch your toes with your legs against a wall?

--ch

12/5 Tuazon

My birthday is now 22 days away. I should just take everyone's blogs until break so I can continue this countdown. 


I am going to be honest--I didn't remember that I had to write the blog again until the very end of class, but rest assured I will make sure you are well-informed about what took place today. 


While Coats-Haan passed out a packet to do tonight's homework on p. 97 of our lab manuel, we checked our homework from over the weekend, which was the Forces and the Laws of Motion: Overcoming Friction worksheet. No one seemed to have any questions about the homework, so we went straight on to our next order of business, which was finishing #6 on our examples sheet.

Before we began, Coats-Haan told us a little fun fact. She said it made her "conceptually happy" to draw triangles with the slope going down to the right (see figure 1) when something is going downhill, as opposed to drawing the slope going up to the right (see figure 2) when something is going uphill . By doing this, the motion of the object will always go in the positive x direction. Coats-Haan says that if you're better at spatial manipulation than she is, however, you can always draw the triangle going a single direction. Either way you choose to go, she won't take off points from your test for the way you draw the triangle. 

FIGURE 1

FIGURE 2 

(I apologize that one triangle is labeled and the other is not. I'm also sorry for the big gap after this figure. I don't know how to fix it.)










Now for #6 on our examples sheet. Coats-Haan began drawing the triangle in the same direction as figure 1. The three forces acting on the skier are a normal force, a gravitational force, and a frictional force going up the slope.


First we start with the three steps:


1. Sigma Fy = 0; N = mgcostheta
2. f = uN = umgcostheta
3. Sigma Fx = ma (Because the skier is not at rest or going at a constant velocity, we cannot set this equal to zero)


Note that we neglect air resistance. In #7 on our pair check, we have to include a 50.0N air resistance in our calculations, yet doing so is not much different than simply adding another force in the x direction. 


The sum of the forces in the x direction (or ma) is the x component of mg minus friction, which ends up being mgsintheta – umgcostheta = ma. All the "m's" cancel out. 


From this we get a = g(sintheta – ucostheta) = 2.76 m/s. Using the fourth kinematics equation, we solve for Vf to get 27 m/s. 


To find time, Coats-Haan says we can use either the third kinematics equation or the first kinematics equation. Again, either way you choose to go, she will not take points off on the test. When you calculate t, you get 8.4 s.


---


While Coats-Haan was showing us how to do the above example, she dropped her SMART Board eraser and had to chase it around behind her desk while mumbling incoherent things to herself. 


Soon afterwards, she dusted herself off and went to the back of the room to explain the Coefficient of Friction lab, for which we have to complete a lab report, due next Tuesday. (Coats-Haan says that there is only one more lab report to do after this one for the rest of the school year. We'll hold her accountable for that.) In a bunch of bins at the back counter there were a variety of wooden blocks, a protractor, a weight, a ramp, etc. We were to use these things to measure the angle at which various items begin to slide down the ramp. 


The remainder of class was spent finishing up our Two Dimension Friction Pair Checks, which we turned in. I was pretty thrilled by working through it. I tried explaining things on the pair check that I myself was trying to understand, but somehow, explaining what I kind-of knew to them helped me to fully understand it now. 


It was a pretty typical day in second period physics. 

THE QUICKIE DETAILS:


Activities:
Checked our homework (Forces and the Laws of Motion: Overcoming Friction, #1-7)
Completed #6 on our example sheet
Finished #5-8 on the Two Dimensional Friction Pair Check (which we turned in)
Started working on the Coefficient of Friction lab, which we will finish up tomorrow

Returned to us:
Nothing (Except for me. I got my blog grade sheet for last Friday's blog returned.)

Checked Homework: 
Forces and the Laws of Motion: Overcoming Friction, #1-7 (a worksheet)

Homework:
Pendulum Lab Report (due tomorrow)
Hewitt Center of Mass questions (p. 97 of lab manuel) based on a packet that Coats-Haan passed out
Coefficient of Friction Lab Report due next Tuesday, 12/13

Question of the Day: 
What are the two situations where the sum of the forces are zero in the x direction for inclined plane friction problems?

Answer: 
Before I answer, I'd just like to say that I wrote this down in the margin of my example sheet with a gut feeling that I would have to know it later.


It is later. 


Two situations where the sum of the forces are zero in the x direction for inclined plan friction problems are when the object is:


1. at rest.
2. moving at a constant velocity. 


In fact, we had one of these constant velocity situations on our Two Dimensional Friction Pair Check in #6-7. Onur and I got the correct answers (without looking at the board), which end up being 675.58 N and  69.12 N, respectively. 

12/5 qod

What are the two situations where the sum of the forces are zero in the x direction for inclined plane friction problems/

--ch

12/2 Tuazon

My birthday is 25 days away––just thought I'd let you know.

But as always, physics calls.

While we were going over homework, Coats-Haan was speaking her mind like she usually does (you understand), and for some reason, she was staring at Jeff and said, "You know why I think fourth period is stupider? It's because I don't have any gingers in it." I suppose she has a point––fourth period did have a class average of 73.10% on the Newton's Laws Test compared to everyone else's 80% and up averages.

As for the homework, someone asked to go over #43, which if you recall is about to a 25 kg block sliding on a frictionless surface with a 4 kg block on its side, and you had to find the push force necessary to put on the 25 kg block to prevent the 4 kg block from falling down. In this problem, friction equals gravity, and you have to use the f=uN equation to help solve this problem. The answer ends up being a 40 N push. If I were you, I would ask Coats-Haan for the details, because there are several forces working in this problem and they are easy to mix up on a blog.

We put away our homework as Coats-Haan passed out a worksheet, which is our homework for the weekend. It's seven problems about overcoming friction, and it doesn't look too thrilling. But as Coats-Haan said today, "I'm sure you had f=uN on last night's homework."

Jeff shook his head. Kelly smiled. Onur stared at her like usual.

After that, Coats-Haan told us to get out our example sheet (which I really insist on calling a packet) to do #4, which asks what force is needed to push a 100 N cartoon [of gumm[y] worms] up a 30 degree incline if the coefficient of static friction is 0.400 and the coefficient of kinetic friction is 0.350.

Now I'm going to warn you, I don't feel qualified to explain this over a blog because I don't have the skill to put detailed visual diagrams in your head. Plus, Coats-Haan even told us in class that grasping the concept may be a little challenging.

Basically, because the problem is set on an incline, we have to turn our x and y axes so that x is parallel to the ground surface and y is perpendicular to the ground surface. By doing this, the normal force, push force, and kinetic friction force are along the axis, and the only force which we need to find the components of is mg.

Next, we made a triangle using mg as the hypotenuse and it's x and y components as its other sides. Using geometry, we calculated that the angle opposite from the x component side is always 90 degree – theta, which is equal to the incline given to us in the problem (30 degrees). The x component = mgsintheta, and the y component = mgcostheta. Now you may be wondering why x is proportional to sin rather than cos like it usually is, but I have made a more detailed expression of why this is true in the QotD below.

Furthermore, there are three steps to solve these incline problems:

1. Sigma Fy = 0

2. f = uN

3. Sigma Fx = ma

The below info is more detailed for this problem.

1. Sigma Fy = 0; N = mgcostheta (This and step 2 are not really steps for Honors Physics because all of our incline problems will always be set up with these conditions. AP Physics may be different, however.)
2. f = uN = umgcostheta
3. Sigma Fx = ma; (which in this problem is P = umgcostheta + mgsintheta = (0.35)(100N)cos(30) + (100N)sin(30) = 80.3 N)

On the examples packet, #5 is similar to #4 because it is on an incline, only you need to use step 3 to solve for u. Also, friction moves up the incline instead of downwards because as you walk, you push back on the ground, and the ground pushes you forward.

For the pair check we got today, Coats-Haan only wanted us to do #1-4 for Monday. She told us that #3, in which we are wearing glass slippers on top of a glass hill, is more like #5 on the examples packet than #4. Onur and I breezed through these questions, but Jeff refused to believe in the possibility of him wearing glass slippers.

THE QUICKIE DETAILS:

Activities:
Checked our homework (see below)
Learned about two-dimensional physics, specifically on an incline.
Completed #4-5 on our examples packet
Worked on Two-Dimensional Friction Pair Check

Returned to us:
1. Pair Check on One-Dimensional Friction
2. Hewitt Reading on Friction (a worksheet)

Checked Homework: 
Textbook homework problems, p.128 #34, 35, 37, 39-44 (Turned nothing in)

Homework for the weekend:
Forces and the Laws of Motion: Overcoming Friction, #1-7 (a worksheet)
Pair Check Problems #1-4 (The rest of the pair check will be finished Monday)
Pendulum Lab Report (due Tuesday)

Question of the Day: 
Why is the x component not always proportional to cos theta?

Answer: 
Cos theta is defined as (adjacent/hypotenuse), which is y/mg if theta is opposite of x like in problem #4 on our examples packet. In this case, y is proportional to cos theta. The x component is instead proportional to sin theta, which is (opposite/hypotenuse) or x/mg.

Therefore in these problems:
sin theta=x/mg, or x=mgsintheta
cos theta=y/mg, or y=mgcostheta (Coats-Haan asked Onur if he was fine with this being true. Onur's fine with it.)

12/2 qod

Why is the x component not always proportional to the cosine of theta?

--ch

12/1 qod

What things affect the coefficient of friction?

-ch

11/30 qod

If your tires lock up when you travel at a high rate of speed on an icy road, what kind of friction exists between the tires and the icy road?

--ch

11/29 Monroe

Nothing was turned in today, however we did get back the group fci diagnostic test (in one of the four group member's folder.) Then Coats-Haan checked the force law practice problems and we compared them to the keys. She proceeded to comment on our class' good attendance, concluding that coming to school is very important and that could be a factor for our grades on tests. After most were done checking the homework, we were allowed to either continue checking the homework, look over the fci diagnostic test, or work on the Newton's law test review.  The reason she gave us time in class to do this was to insure that we were comfortable with the material, so if we had any questions she was open to answer them. Our homework was to complete the Newton's law test review and study for tomorrow's test. Also a reminder that the Pendulum Lab Report is due on tuesday the sixth.
QOD: Your policy on conversion factors are that students should be able to convert within the system and anything else, if needed to be known, will be given on the test.

11/29 qod

What is my policy about conversion factors on tests?

--ch

11/28 Miley

Today was the first day back from break, so nothing was due or turned in. In class we were given two assignments as a group, the inertial pendulum and to retake the diagnostic test. Most groups began with the pendulum lab. The objective of this lab was to remove the gravitational force from a mass and see its effect on the period. We did this by timing the amount of time it took different weights to cycle 20 times. Do to the dangerous nature of this lab, we had to carefully tape the weights and ensure that the pendulum wouldn’t break. Most groups recorded this data down for the lab report that will be due on December 6^th. The next thing we worked on was the diagnostic test. As a group we had to retake the diagnostic test for correctness and to ensure that the members in our group understood the questions. When completed, this was turned in for a grade. Our homework was the Force Law Practice Problems. Mrs. Coats-Haan also reminded us to pick up the Newton’s Law Test Review Guide if you hadn’t already.

QOD: If you were on the space shuttle, what is one way that you could determine the mass of an object?

Similarly to the inertial pendulum lab, we could tape the object to the pendulum and time how long it takes the mass to make 20 cycles. We would repeat this process and take the average time, just as we have done in the lab.

11/28 qod

If you were on the space shuttle, what is one way that you could determine the mass of an object?

--ch

11/22 qod

Which toy was your favorite?  How was its behavior different when it was in orbit than when it was on the Earth's surface?

--ch

11/21

In physics on November 21, we played with toys.  But before that we checked the Spring homework assignment assigned on Friday as well as watched Homer Simpson eat potato chips in space.  We learned why people experience weightlessness, or rather microgravity, in space.  This "microgravity" is experienced during free fall because the velocity of an object falling is equal to the acceleration due to gravity.  That is why satellites orbit earth, they fall around it.  What we did with the children's toys is prepared a presentation to explain how they operate and how Newton's three laws apply to them.  In our class period, we had a slinky race down the stairs although the stairs were too wide for the slinky to move down. 

-Ethan Leonow

11/21 qod

What is microgravity?  Where can we experience it?  Why do we experience it there?

--ch

11/18 qod

What is the first thing you should do when you solve a spring problem and how does this help you determine the sign of the spring force?

--ch

11/17 QOD

Is the spring force constant or does it depend on how far it is stretched or compressed?  Support your answer with evidence.

--ch

11/16 qod

What are the 4 different ways we could solve the simultaneous equations in tension problems and why are matrices the best way?

--ch

11/15 qod

Why do rockets have stages?

--ch

11/14 qod

How does Newton's 3rd law apply to your balloon helicopter?

--ch

11/11 Chao

            Today obviously was a very special day. Just look at the numbers. People screaming wishes and all that just proves it’s special. Well, today in physics was pretty special too.

            Of course, with every special day, the beginning starts out slow, mundane, and routine. Checking the board, we held tight to our papers filled with homework problems (none of which were just old problems with altered numbers) and did not think about the number of trees (or saplings) we potentially affected by using the  paper. Carbon graphite is virtually able to obtain anywhere so we didn’t think about that either. Actually, on second thought, it still takes certain requirements to obtain graphite. So we should probably be feeling a little guilty. But hey, it was for physics. A good purpose.  

            Coats-Haan with her efficiency maximizing at second period already had keys laid out on the desks for us. While checking our answers to page 127 #10 – 17 and musing over our pg. 73-4 and pair checks received back in our blue folders, Coats- Haan looked to see that we completed our homework (mine already littered with red pen corrections). She also remarked how she heard that Carlie was a talkative person despite her quietness in Physics (or was it her dreaming? I don’t remember. I need sleep.).

            After a few questions and remarks and quiet murmurs and probably a few more rounds of “Baa Baa Black Sheep” in Coats-Haan’s head, we commenced with our special task of the day: doing a POGIL with our new groups! Sending a person from each group whose name was at the beginning of the alphabet to grab the folders, Coats-Haan instructed the rest of us to take out pages 80.1-80.6 in our lab manuel. 80.1-80.4 is our POGIL; 80.5-80.6 is a forces diagram worksheet that is homework. Don’t worry: the pages are not split up into 10ths of a normal piece of paper. Coats-Haan simply just added more pages to the lab manuel but could not change the page numbering.

            The POGIL was about forces and how different types of forces act on an object. There’s gravity (which acts downward on an object), normal force (which is always perpendicular to the surface and upwards, only exerted if there is a surface beneath the object), tension (which is instigated when an object is hanging from a rope or string and is always oriented upwards), and friction (which is instigated by motion and acts in the direction opposite of the motion). Certain situations dictate when each force acts. For example, if an object is at rest and suspended, there is no normal force or friction acting upon it, only tension and gravity. On the other hand, if an object is sliding down an inclined plane, there's gravity acting straight downwards, normal force acting perpendicularly upward, and friction acting in the opposite direction. 

Stop signs dotted the page as we worked our way through the POGIL, sorting disagreements on the direction of normal force and on the application of tension. At 9:13 exactly (I know, not 11:11, that would have been cool), Coats-Haan stopped us and went over 80.3, the page with all of the diagrams. We had to draw the forces that each object exerted. Halfway through explaining the diagrams, the bell suddenly rang, ending our special day with POGIL.  Coats-Haan will finish explaining Monday. Still, do the homework. It’s important.

Question of the Day:

How is the normal force oriented to surfaces?

The normal force is oriented in a way that is always perpendicular to the direction of the surface and upwards, I believe. For a flat plane, the normal orientation is straight up, 90^o, stock straight. For an inclined plane, the angle of the normal force is slightly different but still in the general upwards direction. 

11/11 qod

How is the normal force oriented to surfaces?

--ch

11/10 Back

As I walked into Honors Physics for second period on November 10, 2011, I checked the all-knowing white board to find out where my homework from the previous night was to be placed. It instructed me to turn page 73-74 from the lab manual, which I did in the blue second period folder. Next on the board was to check the problems (we never do the questions) from page 127 in our textbook. We had been assigned to complete problems one through nine. After a short questioning session on the assignment, CH had our class take additional notes on Newton's 2nd Law of Motion. Well, actually, there were no extra notes. However, CH pointed out, we did have two problems from the example sheet to work out. After discovering how to be FOXY in physics (we learned by examining three forces that were acting on an object and applying ROXY with forces),) CH gave us a pair check to complete with our lab partners. It was a momentous occasion, being the first pair check since the infamous seat change (FSD4L!) As we worked our way through the pair check, which turned out to be pretty simple, CH handed back our quarter tests. As my table members and I rifled through our tests, however, we could not figure out why we had gotten two questions wrong. I brought the two questions to CH, and she decided that we were right, her key was wrong, and we all deserved two extra points on our exam grades. After the discovery of these mistakes, we began to work on our homework, the problems 10-17 on page 127 in the textbook. We all promised CH to actually do the homework and not just turn in the old homework with altered numbers.


QOD: If you have several forces acting in multiple directions on an object, how do you determine the object's acceleration?
In order to determine the objects acceleration, you set up a ROXY table. However, you must replace the R with an F, for force. Then, you proceed as if the table used ROXY. You add the separate x and y components and then use the Pythagorean Theorem to find the magnitude of the acceleration. You then take the inverse tangent of the two components to find the angle at which the acceleration lies.

11/10 qod

If you have several forces acting in multiple directions on an object, how do you determine the object's acceleration?

--ch

11/9 Armour

In Class: Today in Honors Physics, we took notes on Newton’s first and second laws of motion, watched a JSM video on Newton’s Second law and we did a corresponding worksheet to the video.  Today in class I got scared because Coats-Haan called me out for not know the difference between weight and gravity and wasn’t really paying attention so I had no idea what she was talking about.

Notes:

Classical Mechanics

·         Describe what happens to things as small as an atom to as big as a galaxy

·         Apply in a non-accelerating reference frame(which is the definition of an inertial reference frame)

Force

·         Push or pull

·         Something that causes an object to accelerate

·         4 types of forces: gravitational, electromagnetic, strong nuclear, and weak nuclear

Newton’s 1^st law

·         If no forces act on an object, it will have zero acceleration

Inertia

·         The tendency of a body to maintain its state of rest or uniform motion

·         The first law is sometimes known as the law of inertia.

Mass

·         Is a measure of the inertia of an object

·         Is not the same thing as weight

·         Can only be defined in terms of how we measure it.

·         Is an additive scalar property

Mass Units

·         SI: kilograms

·         cgs: grams

·         English: slugs

·         Pounds are a unit of weight, not a unit of mass

Newton’s 2^nd law

·         ΣF=ma

·         a= acceleration (vector)

·         m= mass

·         ΣF= vector sum of all the forces acting on the body

Units

·         ΣF=ma

·         SI units: Newton= Kg x m/s²

·         cgs units: dyne= gram x cm/s²

·         English units: pound= slug x ft/s²

Papers Back: Inertia ball, JSM Inertia: Newton’s First Law, Diagnostic Test

Assignments:  Newton’s 2^nd law on pages 73-74 in the lab manual and page 127 #1-9 in the textbook

Turned in: page 63 (take home lab) and pages 71-72 from our lab manual

QOD: How are mass and weight different?

Mass is the amount of matter an object has and is a measure of the inertia of an object, while weight is the measure of the force of an object when exposed to a gravitational force.

11/9 qod

How are mass and weight different?

--ch

11/4 qod

Explain how Newton's first law applies to one of the many demonstrations today.

-ch

11/3 Shah

           On this relaxed morning of Thursday November 3, 2011, we did not have anything to turn in since it was the first day after exams. However, due to Coats-Haan unparalleled grading speed, our exams were waiting for us in our folders.
            As we sat down, we were overwhelmed with various papers and packets, including the blue bonus sheet for 2^nd quarter, a fci diagnostic (which is homework), and a farewell sheet. Yes, today was the last day we spent with our team from first quarter. We all wrote thoughtful comments about our team members, cherishing our last few moments with them. As we began to get new seats, Coats-Haan said she was about to cry because of Jeff, Charlie, Ethan, and Trevor’s group. They had a little team huddle thing going before they split.
            After we all settled down in our new seats, Coats-Haan gave instructions on the inertia ball activity we had to do in class today. We would be maneuvering a heavy bowling ball through a course that looked somewhat like a tootsie roll. The goal was to move the ball along the path as quickly as possible without 1) knocking the ball off the path 2) hitting the surrounding 2 liter pop bottles 3) touching the ball with your foot or 4) overshooting the box in the end, all while attempting to get the fastest time.
            After a plethora of students attempted this difficult task, Jeff ended with the fasted time of 36 seconds, Alexis had the slowest time of 96 seconds, and Carlie had the greatest penalty time of 24 seconds.
            Random fact of the day: so today in physics history votes were counted electronically for the first time in the U.S. presidential election in 1964 and the largest road accident in history occurred when a tanker in Afghanistan overturned and killed 176 people (although I don’t understand how the second fact correlates with physics).
            For homework tonight, we had to complete the fci diagnostic test, a relatively short 30 multiple choice question test. However, remember to answer using 1-5 instead of a-e, because the packet was set up weird and it’s just too time consuming to change it.
            For the question of the day: We had to apply a force to keep the bowling ball on the inertia ball track in the beginning to get the ball to initially move, when we were turning the corners, and at when we needed to slow down or stop the ball.

11/3 qod

When did you have to apply a force to keep the bowling ball on the inertia ball track?

--ch

10/28 qod

What part of 1st quarter do you feel like you need to review the most for next week's exams?

--ch

10/27 Shi

This morning, CH was on her A-game so to speak. She approached our table in the same calm and refined manner as usual and looked around for the book problems (pg 84 #47-57) when she realized that I didn't have my homework problems laid out on my desk. Being a crafty and resourceful student, I took it upon myself to present something-- a token offering in a sense. Because, as everyone knows, something is better than nothing.

Not today.

As I pulled out my physics homework today, something strange happened. It morphed from the actual homework into yesterday's homework (but with numbers 47-57) for some reason. I didn't know what was going on but when CH saw my homework she did a double take. Just like Sherlock Holmes, she used her discerning eye and then realized that that wasn't the homework that was due today but was in fact yesterday's homework disguising as today's homework. Appalled by this, she exclaimed "Sonny, you're a slime-ball." I was also surprised by this strange event. However, as I glanced around the room, I realized I was once again in the infamous Room 266!

Looking up, I realized that the all-knowing board was back. On it it prophesied "Turn in HAC check and Blue Sheet", "Check pg 84 47-57", and "Turn in Pair Check". Just as before, we did all of things that the board beckoned. How exactly the board knew this is still a mystery to me. CH went over questions two, three, and four, all of which I got correct (of course). We then went on to finish the pair check. After which, she asked if we had any questions over the homework. This was the part of the class in which I sat awkwardly without any homework to actually check. Luckily, this only lasted for a short while and we were soon on our way to working on the reviews. Which, incidentally, are both due tomorrow! Isn't that exciting?

Also, there's review session after school on Friday in CH's room if you would like to review. Bring in questions to ask or you'll be sitting there with nothing to do.

QOD: In relative motion problems, we have to add vectors. How do you know when to use ROXY? --ch

When vectors aren't going in the same direction or in opposite, it's appropriate to use ROXY. ie. When wind is blowing in a direction perpendicular to the plane. That creates a right triangle which is needed in ROXY equations.

10/27 qod

In relative motion problems, we have to add vectors.  How do you know when to use ROXY?

--ch

10/26 Shah

On this lovely morning of October 26, 2011, we started our day in 2^nd period Honors Physics by turning in the Aristocracy questions worksheet and checking the questions from the book (page 155 #1-10). Then we began to take notes on relative motion. The notes were:

• Reference Frame
• Reference frame—an object that is assumed stationary that is used to analyze the motion of other objects
• This is like when sometimes you are waiting at a traffic light and the car next to you starts moving, so you slam on the brakes just to realize that you were never moving to begin with. Of course, Coats-Haan and I were the only ones in class who have done that.
• No object is truly stationary
• The Earth is the most commonly used reference frame.
• Mathematical Perspective
• (there was a picture of triangle ABC with
• The 1^st letter is where the object ends.
• D_CB & D_AC are vectors with heads and tails, so…
• D_AB = D_AC + D_CB
• Remember, the pattern always stays the same: A is in the beginning, B is at the end, and C disappears.
• This also follows the pattern that if you dived through by Δt, you get…
• v_AC= v_AB + v_BC
• Also, note that v_AB = -v_BA
• Planes
• Tailwind—when the plane flies in the direction of the wind
• Headwind—when the plane flies directly into the wind

As we continued to the pair checks, Coats-Haan mentioned how she wanted to be like Chris and that she sounded like Sonny today. Then we started what Coats-Haan consider one of the toughest pair checks we will do all year. We spent the rest of class attempting to finish it, but almost no group finished. We will spend time tomorrow in class finishing it.

For homework, we need to fill out the HAC sheet, find out blue sheets and fill those out for extra credit, and do #47-57 on page 84 of the book. Also, you may want to get a head start on both the non-linear test review and the 1st quarter review packet, which are both due Friday.

QOD: The magnitude of the ground speed is greater than the magnitude of the air speed. When we drew a vector of the velocities, we see the component vectors (air speed and wind vectors) cross to form a right angle, so the resultant vector (ground speed vector) would be the hypotenuse of the triangle. The hypotenuse of the triangle is always longer than either leg, and since the ground speed vector is the hypotenuse while the air speed vector is a leg, the ground speed vector will be greater than the air speed.

P.S. I don't know why the post is highlighted in white against the green background. I don't know what I'm doing wrong or how to fix it, but it's really bothering me. Sorry.

10/26 qod

According to the compass on a plane, it is flying due north with an airspeed of 300 mph.  A wind is blowing due east at 85 mph.  Is the magnitude of the ground speed greater than, equal to, or the same as the air speed.  Explain your answer.

--ch

10/25 Scheitlin

      In physics class today we had to turn in our dart gun lab report and our follow up Barbie lab questions. Then we immediately went to writing notes on uniform circular motion. A few key points in the notes were that the acceleration is always directed toward the center of the circle and the magnitude of acceleration is a = v^2 / r, where v is the speed and r is the radius of the circle. Also the period (T) is how long it takes an object to move around the circle and the frequency (F) is how many times the object goes around the circle in a given time. Frequency and Period are inversely related. The equation is v = (2 * pi * r) /T or v = 2*pi*r*F. We also did a few examples on the example worksheet. Oh and while we were taking notes we found out that Austin can rotate his arm in a circle the fastest.
     After notes we were given a pair check which was to be completed and turned in and any extra time we had we got to work on our homework. For tonight we have to complete page 155 # 1-10 in the textbook, Aristotle questions, HAC grade check, and the exam review and test review are due Friday. Also if we return all of our tests back in on exam day we will receive a few extra points.
Question of the Day: What does it mean we talk about the number of g's?
Well, I believe it is the acceleration of an object divided by acceleration due to gravity

10/25 qod

What does it mean we talk about the number of g's?

--ch

10/24 qod

Is 8 m/s an achievable speed for a person without mechanical aid?  If so, is it a running or walking speed.  Justify your answer.

--ch

10/21/2011 Patricia Nyaega

Walking into class today we noticed that there were no papers that were to be handed in neither were there any papers that were to be collected from our folders. We did, though, have to place our "Another Detailed Analysis" on the table so that Coats-Haan could quickly come around and check for its completion. This detailed analysis was given to us the day before, and many of us completed it in class. Coats-Haan then asked the class if there were any questions concerning the detailed analysis, there were none and we moved on to a new and exciting task. Coats-Haan had, the day before, set up a scale model of a "crime scene" . In it was Barbie Einstein laying dead next to a hotel pool. She had fallen from the eighth floor, and we had to determine whether it was a homicide or suicide using our knowledge of projectile motion. Each table was given four minutes to approach the crime scene and take measurements. Our conclusion and measurements were to be placed on a white poster board and we are to present our findings to the class on Monday. Our homework was to complete our crime scene investigation. We also have a lab report due Tuesday, October 25th, and our quarter review as well as our projectile motion review packets are to be completed by Friday, October 28th.

Question of the day: How did you calculate Barbie's horizontal velocity when she left the hotel window?
To calculate Barbie's horizontal velocity you must first find her intial speed and then multiply that quantity by the cosine of zero.

10/21 qod

How did you calculate Barbie's horizontal velocity when she left the hotel window?

--ch

10/20 Monroe

Today we had nothing to turn in nor anything to get back. At the start of class, Coat-Haan passed out the answer key to the homework, the first quarter review packet and another detailed analysis. First we compared our homework answers to the answer key. Many students struggled on  the homework, but no one came in for help therefore there was no excuse. Coats-Haan hinted that we should try harder to be her best testing class, especially for friendly rivalry like Aimee and Ashley Miley as well as others. Next she explained that our first quarter test review will be due next Friday. She is giving us more time for review because we also have a test on that Friday. Then she reminded us that our lab report for the dart gun lab is due on Tuesday the 25th. We proceeded to then start the detailed analysis as a class, doing the sketch. From there we worked as a table in order to complete the analysis. This analysis helps us break down the problem into little steps to make sure we understand and can compute any type of question asked from the original problem. If it was not completed by the end of class, it needed to be finished for homework.
QuestionOfTheDay: The x values must be equal and the y values must be equal for the two balls to collide, so for our problem the balls do not collide.

10/20 Leonow

Today in class, we first checked the homework due today.  The assignment was page 82 14-23.  Then, we worked productively on a second detailed analysis of a projectile problem.  This one had 39 questions.  If we did not get that done, it was assigned for homework.  In addition, we received the first quarter review packet which is due next friday.  There will be a test on projectiles and a review packet for chapter 3 due next friday as well.  The key to the first quarter packet will be posted after the packet is collected.  Mrs. Coats-Haan told second period we need to step it up or we will fall behind third and seventh period.  She encouraged to come in and ask questions if needed in the morning.

The answer to the question of the day is the x values and y values both have to be equal at that instant in order for the balls to collide. 

10/20 qod

In the problem that we worked on today, what do you know about the x and y coordinates of the two balls when they collide?

--ch

10/19 qod

Use the range equation to explain mathematically, why complementary launch angles produce the same horizontal range.

--ch

10/18 Miley

Today’s class began with going over questions #1-16 in the Detailed Analysis packet. After this, Coats-Haan gave us the rest of class to complete the Detailed Analysis packet. During this time we were allowed to use our group members and the key as a reference on how to complete the problems. When most of the class reached problem #38, Coats-Haan gave us notes on the last kinematics equation. The last kinematics equation is range: R= V^2sin 2(theta)/g. In this equation V stands for speed and it can only be used if both Yf and Yi are the same. The numerical value for g is +9.8 m/s. After learning about the last equation, we were given time to continue the packet. It was at this time that Austin introduced his group members to his penguin eraser. If the Detailed Analysis packet wasn’t completed in class it became homework for the night.

QOD: To begin determining if the ball reaches the maximum height before or after it reaches the edge of the cliff you must determine the amount of time required for the ball to reach the top of its trajectory. This can be done using the 1^st kinematics equations which results in an answer of .587 sec. Then you must calculate the horizontal distance that the ball travels during the time it takes to reach the peak. This can be computed by using V= change in X/ change in T which gives you an answer of 5.85 m. The horizontal distance between the edge of the cliff and the initial X position is 5m (this is a given value). So to compute where the ball reaches its maximum height you can subtract 5.85-5 to give you an answer of .85. This means that the ball reaches its maximum height .85 m past the cliff.

10/18 qod

What are the steps to determine if the ball in today's problem reaches its maximum height before or after it reaches the edge of the cliff?

--ch

10/17 Wheeler

Today in Honors Physics, the class of brilliant students (and a brilliant teacher, by the way), we learned a new concept. A concept about the interworkings of projectile motion. I know, it sounds pretty scary. But, guess what? If you completed the Hewitt Chapter 3 questions and the cartoon guide questions that were assigned on Friday for homework (which were due today), you already have a head start on understanding the interworkings of projectile motion. And, to make your day even brighter, the concept is really only half new because just like we used ROXY to find vectors, we can use ROXY to find the initial horizontal and vertical components of velocity. I found that to be pretty exciting, particularly since my brain tries to slack off when it comes to learning new concepts on Mondays (and sometimes on Tuesdays, just because they follow Mondays). Now, I know you are having a hard time keeping your composure because you are so excited about the interworkings of projectile motion, but for homework, we are assigned the first sixteen problems from the worksheet "Detailed Analysis of a Projectile Problem," which we even had time to finish in class. Yes, in class. All of the problems, too. Not just half, all of them. I was jumping for joy, similar to the way Coats-Haan looked when she was looking at the picture of Julius Sumner Miller holding a rifle in his lab that was embedded in her notes presentation. She was probably just as excited, if not more excited, than I was about going home with no homework. Anyways, during this notes presentation that Coats-Haan gave us, we (obviously) took notes and we also tried a few examples to help us understand the concept. A highly emphasized point in the presentation is that horizontal and vertical velocities are indepedent of each other. Neglecting air resistance (NAR), the horizontal component velocity is constant. Also, NAR, the vertical component velocity is only affected by gravity. I just love this whole "NAR" thing--it shortens the amount of words needed to convey the concept, and it also is the first three letters of "narwhal." NAR is cool in my book. Moving on to the question of the day now...

QOD: Does the horizontal or vertical component of velocity affect time more?
Answer: Well, it is sad to say it, but I am not entirely sure what the answer is. However, I believe it is the vertical component of velocity because it is affected by gravity, which accelerates at -9.8 m/s squared. The horizontal component is not affected by gravity, it remains constant (NAR).

10/17 qod

Which component velocity of is going to affect time more, vertical or horizontal?

--ch

10-14 Tamayo

Today in class we got back our checked Acceleration vs. Time Graphing Packet and our Linear Motion Test Review. We turned in our lab reports, which were assigned to us last Friday. After we turned in our lab reports Mrs. Coats-Haan gave us our homework which included a reading printout with a separate question sheet and a question sheet for a cartoon located on page 50 in the Lab Manual. After this we were given a lab report that belonged to  someone else in our class. We were given a rubric for grading our classmate’s report. After peer grading the reports Mrs. Coats-Haan allowed us to take a class vote as to whether or not the reports should be counted for a grade. Our class voted not to count them for a grade. Mrs. Coats-Haan was very kind in still agreeing to grade them so we would know what we need to change for  the next time we have to create a lab report. The next thing we did in class was took a ruler with a penny on the edge of it and another penny on the edge of the table and used the ruler to shoot the penny off the table. This activity was supposed to show that an object moving horizontally from the same height as an object dropping straight down hit the ground at the same time. However, this was not easy to perfect but Jeff was able to do it pretty good. Next Mrs. Coats-Haan gave us a demonstration. Using a special car with a tube and a compressed she placed a ball in it. When she pushed the car she pulled the pin holding the spring releasing the ball into the air. The result being the ball was shot in to the air but came back down in the tube of the moving car. After the demonstration we watched our first Julius Sumner Miller video. Mrs. Coats-Haan was so excited to show us this video, she had to stop the video three times in the first fifteen seconds to explain a few things that we needed to know before watching the video such as the fact that we had to complete page 49 of our lab manual before during and after the video. After the video we had five minutes to get started on our homework then class ended.

Question of the Day: What was the point of the experiment with the penny and the ruler?

Answer: The point of the penny ruler experiment was to demonstrate that gravity has the same downward effect on objects moving horizontally and directly downward. Both pennies should have hit the ground at the same time even though one was moving horizontally and one was moving straight down.

10/14 qod

What was the point of the experiment with the penny and the ruler?

--ch

10/13 qod

If you fire a rifle from an elevation of 1 m and drop a bullet at the same time from the same elevation, which bullet will hit the ground first, neglecting air resistance?

--ch

10/11 Harrison

Today in physics was a pretty simple day of completing any work that was due by the end of the week. First, Mrs. Coats-Haan passed out the answer sheet to the previous night's homework (p. 55 #57-62 in the text book) and went over any questions students didn't understand. We didn't receive any papers back today. The rest of class was basically free time to work on any of the physics work due by the end of the week, which, for me, included working on the graphs lab on the computer. Other options included working on the Linear Motion Test Review packet due on Thursday or the Free Fall Lab write up that is due on Friday. We also have a Linear Motion test on Thursday.

Question of the Day: What does it mean when the sign of acceleration and velocity are the same?  What does it mean when they are different?
If the sign of the acceleration and velocity are the same, then the object is speeding up. If the signs are different, then the object is slowing down.

10/11 qod

What does it mean when the sign of acceleration and velocity are the same?  What does it mean when they are different?

--ch

10/10 qod

How do you find acceleration from a velocity vs. time graph?

--ch

10/7 Eroglu

       Walking into Physics in the morning I noticed that it said to check "1st Quarter Honors Physics Review Problems". I'd completed the final word problems of a POGIL as well and was extatic to learn that we weren't going to turn it in. Coats-Haan passed the answer keys to the review problems out, as she has for every checked homework assignment. Problem number 5 included mass, something I had never seen before in this Honors Physics class. To find out that I had, in fact, correctly worked through this problem was very rewarding although as I'd found out the night before, mass was really not a factor in this problem.
        Coats-Haan directly stated that we had a large amount to accomplish during class and that we only had time to go over two problems. After this, she set out to explain the the "Acceleration of Gravity" lab. To do this lab, my group was told to move to another table because our regular table doesn't give us access to an outlet. In the lab, we were to measure distances, calculate average velocity for intervals of time, and plot this average velocity on a graph of velocity vs. time; moreover, the graph would enable us to determine the accelearation due to gravity. Of course we already know that this is -9.8meters/second squared.
         To do this, we plugged the timer in and placed the timer at the edge of our table. We then thread a 1.5 m strip of paper throught the slot on the timer. We had to arrange the materials so that when the timer vibrated, the striker would hit a carbon paper disk with the paper strip underneath it. Because of this, a dot was marked on the strip of paper each time the timer struck the carbon paper. The dots were separated by a distance equal to the distance which the strip moved in one time interval.
         To cause the strip to move through the timer, we attached a 1-kg mass to the end of the paper strip. Chris turned the timer on and Kyle released the mass. Once the mass hit the floor, Chris turned the timer off. Jack removed the strip from the mechanism and we noticed that the motion of mass was recorded through dots. Looking at the dots, we notice where increased separation first became obvious and numbered that dot zero.
          We numbered all dots after that one until 17. We then made a data table with the dot number, position, change in position(cm), time interval(sec), and average velocity(m/sec). To answer the question "How can you tell when the weight was moving the fastest by looking at the ticker tape timer?" I say that ,because the time interval is always 1/60 sec, the bigger the change in position of the dots is, the higher the average velocity. In response to the question, "How are you going to calculate accleration in this lab?" the average velocity and time interval will be graphed in a velocity vs. time graph. Two points will be marked on a line drawn through the data on the table. The change in velocity/the change in time will yield acceleration due to gravity. The homework is to do page 54 #s 30,31,33,47,49,51,77,78. The "Acceleration of Gravity" lab report is due on 10/12.

         

10/7 qod

How can you tell when the weight was moving the fastest by looking at the ticker tape timer?  How are you going to calculate acceleration in this lab?

--ch

10/6 Dombrowski

In Class: today was yet another normal day in Mrs. Coats-Haan's 2nd period honors physics class. We spent all of the class period on the Free Fall POGIL, found on page 41 of the Lab Manual. This POGIL involved calculating and graphing a balls velocity and height at different times as it traveled 80 meters in the air from "your" hand, which is quite impressive by the way. We used the equations from our kinematics card, which is quite useful! The POGIL was homework if your group didn't finish it during class. Our group's work consisted mostly of Onur and Chris arguing over how to do each calculation, while I "encouraged" Kyle to figure it out before them. Unfortunately Coats-Haan frowns upon my methods of "encouraging" the group to work harder. However according to my economics teacher, "People respond to incentives in predictable ways" and we usually get close to, or finished with our in class activities as a result.

Papers Back: None

Assignments: Finish POGIL and the "1st Quarter Honors Physics Review Problems" worksheet.

Turned In: The completed Bleacher Lab write-up

QOD: _____

10/6 qod

What are the patterns in free fall that you discovered today?

--ch

10/5 Chao

MY THOUGHTS AT THE BEGINNING OF CLASS

            Thank goodness the board said “Check p. 54 #37 – 46” because I surely did not understand some questions. Oh, and we get our 2.4-2.5 guided readings back…and our Kinematics tests. Oh, don’t forget to turn in the pair check from yesterday. Wait, I already did that. Did I? Clearly I need sleep.

WHAT REALLY GOES ON IN CLASS PART 1

            Those two aforementioned papers will be waiting for any reader who was absent today in his or her folder, waiting to meet the hungry eyes. Using our handy dandy keys that Coats-Haan passed out to us and our partners, we checked over our homework from the previous night. While doing that, Coats-Haan passed around calculators with the QUADFORM program on them. Sonny helped our table link our calculators with this shortcut way to enter numbers for the quadratic formula.

            The notorious number 44 was a common question that left some of us befuddled. With her handy-dandy SmartBoard, Coats-Haan explained that when an object is thrown up in the air from some initial height and with some initial velocity, the endpoints of the objects’ journey are the endpoints that truly matter because at that certain height, whether the object is traveling up or down, the velocity will be the same and to find the end velocity, use V_f = V_i + at. A in this case will be -9.8 m/s², the acceleration constant for Earth’s gravity.

           As usual, Coats-Haan had a lot planned for us to do today so we didn’t get through everyone’s questions. If you, reader, would like to go ask Coats-Haan to explain some questions to you that you had trouble on or just to visit her with some stolen flowers, that is perfectly OK to happen between 6:30 to 7:30. She’ll be waiting.

            After the usual homework checking and Patricia and Sonny’s usual conversations about general “senior” things, Coats-Haan showed us a YouTube video. While it was loading, Coats-Haan let out all of the frustration she has about Lakota technology. Many of us would agree, even you, reader, perhaps, that Lakota technology just, well, isn’t the best. After a few long moments, Coats-Haan showed us a 1970’s experiment done by astronauts during the Apollo missions. Now of course, the video quality was slightly not up to par, considering that cell phones these days have “a thousand times more memory” than the cameras and computers used to power the Eagle, according to Coats-Haan. The video showed an astronaut holding in his hands a hammer in one and a feather in the other. Coats-Haan told us that because of air resistance and our atmosphere, Galileo’s postulate does not seem to be true regarding two different falling objects. If the hammer and the feather were dropped in our classroom, the hammer would meet the ground first. However, this astronaut daringly and gingerly let go of the two items and well, Galileo’s right after all. They both land at the same exact time onto the moon’s dust-laden ground. It’s hard to tell from the fuzzy, pixilated footage but yes, the feather lands right beside the hammer from the same height.

            Next, we moved on to a different topic known as linear regression, which leads me to the question of the day.

QUESTION OF THE DAY

Coats-Haan (a.k.a. ch) asked, “What is the point of linear regression?”

My answer: The point of linear regression is to minimize the amount of displacement of a point plotted on a graph based on data and the distance of the X and Y coordinates from the true line of best fit. In other words, we use linear regression to find the best line of best fit that would most accurately represent the data that we obtained, since there can be so many lines of best fit drawn through a set of data. For linear regression, the r value when inputted into a calculator is ideally 1 because then the linear regression is a perfect line.

MY THOUGHTS AGAIN

            What’s a derivative and she’s taking the derivative of what? Oh, she told us to not worry. This is calculus related.

WHAT REALLY GOES ON IN CLASS PART 2

            There’s one rule of simple logic in physics we will never break when it comes to graphs: we never connect the dots. Period.

            Coats-Haan pulls up a TI-84 calculator program and we can see what she’s doing as well as her key history. She shows us that we can use some data and the calculator will help us calculate linear regression. First we press STAT, choose option 1: Edit, then enter our X values in the L1 column and our Y values in the L2 column. This table will help us determine the linear regression. It serves as our list and if you want to clear an entire column, you simply select a value of that column, go up until L1 or L2 is selected and press CLEAR. After our list is complete, we select STAT again, this time switching to the CALC menu in which we select option 4: LinReg (ax + b). Pressing ENTER will reveal a menu like this

            LinReg
            y = ax + b
            a = …
            b = …
            r² = …
            r = …

            If the r² and the r values do not show up, select 2nd 0 to select CATALOG, then go the D options and select DiagnosticOn. Ideally, r should equal 1.

            This material will be on the test and we will have to know how to do it or else it is a “fail” (her words, not mine). Expect this material on the test next Thursday the 13^th.

            Then, Coats-Haan asked each group to grab a golf ball, p. 39 of our lab manual, and a timer. We stole quickly and quietly through Main Street to go to the stadium (Patricia and Sonny still jabbering away about their “senior” things). The “most coordinated” person stood at the top of the visitors’ bleachers to drop the golf ball. The “second most coordinated” person stood at the bottom along with the rest of the group timing and tossed the golf ball up to the “most coordinated person” (all her words, not mine). Miranda is obviously the most coordinated person as declared by Coats-Haan. My table sent Jasmine up, since my coordination clearly renders me unable to catch something (have you tried throwing me a football?) and she indirectly volunteered.

            Since we only had 15 minutes, we did three trials in which we timed each one and then we headed back. It was nice outside except the grass was extremely dewy and half of the bare patches were covered with mud. Our golf balls looked more brown than white by the time we finished timing our trials.

            That about wraps up what happened but before I forget, there’s something that has to happen AFTER class right?

HOMEWORK

            We received a linear regression practice worksheet in which we use the calculator to figure out the line of best fit (linear regression) for two sets of data and graph them on the back. We also have to complete a report (on notebook paper or the back of the lab manual page).