Wednesday, February 29, 2012

Tuesday, February 28, 2012

2/28 qod

You have a battery connected to a bulb in a complete circuit.  What do you know about the flow through the circuit?

--ch

Monday, February 27, 2012

Saturday, February 25, 2012

2/24 Chao

I must have been in a very comatose state when I went home yesterday because I did my blog a day early. I’m still in a slight comatose state but, you know, things just happen.

Either way, today’s board with its purple message stated that we had keys waiting on our desks for our electrostatic force worksheets. #12 was a pretty difficult problem. That’s one to review in my opinion.

After answering some questions, especially regarding pesky #12, Coats-Haan gave us a teacher talk regarding the science courses we could take next year. Everyone should take Honors Anatomy because in her words, “Everyone needs to know about their own body.” Advice ranged from “I will not recommend anybody for Earth and Space Science” to being politically correct about a certain half of the kids in our grade that took Chemistry last year.

Then came the AP Physics talk. She stated that the class is very difficult and that mechanics, all the stuff we spent from August to February learning, would be covered in just a few short weeks when school started for us next year. Those that plan on taking AP that is. Tiger moms have some influence, I guess.

She emphasized that she did not want us to start the AP review packet until the weekend before school started. And she looked at me. Don’t worry, Coats-Haan. I may not be in a comatose state during those last few weeks of summer, but I certainly don’t have motivation to start review packets in May.

After the teacher talk session, we jumped into our next activity: the 12-page lab from pages 141 to 160. This lab is split up into several sections, each examining a certain aspect of electricity and circuits. We will be working on this lab during the next few weeks. Every exercise / homework problem must be done on a separate piece of paper. It is essential that we label our papers clearly.

We began section 1 by examining all of the different possible ways to light a light bulb with one bulb, one wire, and one battery. Then, we were supposed to start examining a flashlight. We learned that a circuit to light the light bulb is made when the light bulb is wrapped in wire and it is touching one end while the wire is touching the other end.

There is no homework this weekend but there is a quiz on Monday over Coulomb’s Law and other information regarding the worksheet we checked.

Question of the Day: What is your operational definition for a circuit?
My operational definition for a circuit would be first to obtain a battery or other form of stored electrical energy with a positive and negative end. Obtain metal wire since it conducts electricity easily. If the circuit is concerned with powering a certain device, attach the wire to the device. Have the device touch one end of the battery and have the rest of the wire touching the other end of the battery. I think this is the operational definition, although I’m not sure.

Friday, February 24, 2012

Thursday, February 23, 2012

2/23 Armour

*This is awkward because it was actually my day because Jeff and I switched, so I am going to post my version of the blog for february 23rd also.

Today in physics, we learned more about electrostatic subjects. However, first we turned in our homework from the night before (reading guide). Then we took notes about coulomb’s law, superposition principle, and conservation of charge. The notes are below. Mr. Ebersole handed out the practice problems sheet and we completed that together as a class. Then we worked on the pair check, if one finished then you got to work on your homework. It was a very exciting day in physics.
Electrostatic Notes
1. Coulomb’s law
a. Consider two static point charges
b. Each charge experiences a force along a line connection the two charges
c. The magnitude of the force is given by:
i. F=k|q1||q2|/r2
d. Where k = 8.99*10^9 n*m2/c2
e. q1 and q2 are the magnitudes of the two charges
f. r is the distance between the charges
2. Superposition Principle
a. We can add the electric forces as vectors
b. Opposites attract
c. Like charges repel
3. Conductors- readily conduct electric charge from one point to another i.e. metals
4. Insulators- charge placed on one part of the surface remains localized i.e. wood, rubber, and glass
5. Conservation of Charge
a. Although charge moves from place to place, net charge is never created or destroyed
6. Basic Units of Charge
a. Electrons have a mass of 9.1*10^-31kg and charge of -1.6*10^-19
b. Protons have a mass of 1.67*10^-27 and a charge of 1.6*10^-19
Q.O.D.
What does superposition mean?
Superposition means we can add the electric forces as if they are vectors.

2/23 Chao

            Mr. Ebersole’s right. We kind of need to wake up. Or at least I need to.
            Almost sleepwalking into physics today, I dropped my pile of books onto my desk and of course, my eyes habitually glanced at the board. We turned in our 18.1-18.5 guided readings and out of the blue folders came our “Electricity Stuff” worksheet and our homemade roller coaster grades / problems.
            Then, Mr. Ebersole put up lightning strikes on the SmartBoard and held a balloon (inflated of course) and a piece of rabbit fur. He then rubbed the balloon with the rabbit fur. Nothing elaborately confusing. But the next thing he did certainly had all of us captivated.
            He moved the balloon toward an empty pop can. The empty pop can followed the balloon when he moved the balloon further away from it! After several more tries, he successfully had the balloon freely move the pop can, similar to enamored couples freely following each other in the hallway. Kyle thought it was magic. I did too.
            He explained that because a metal allows electrons to move freely about it, the pop can can create a positive side and a negative side. He also explained that since the rabbit transferred electrons to the balloon and resulting in a negative charge, the pop can’s electrons fled from the electrons from the balloon and thus, the side closest to the balloon had a positive charge. This positive charge, combined with the fact that opposite charges attract, caused the can to move toward the balloon.
            We then popped into notes. Terms like Coulomb’s Law, Superposition Principles, Conductors, Insulators, Conservation of Charge, Basic units of charge came up during class.
Coulomb’s law is essentially saying that the force exerted by 2 static point charges is measured by F = (k * |q1| * |q2|)/r2. K is the constant 8.99 x 109 Nm2/C2. Q1 and q2 are charges measured in Coulombs and r is the distance between them in meters. Similar to the Law of Universal Gravitation.
            The superposition principle (Question of the Day “What does superposition mean?”) simply states that electrostatic forces are vector quantities, with a magnitude and direction. Thus, superposition means that we can add these electrostatic forces in a FOXY table since they are vectors.
            Conductors can readily conduct electric charge from one point to another while insulators can’t. Charge, like energy, is conserved and only moves from place to place, not created nor destroyed.
            Basic units of charge are electrons (mass = 9.1 x 10-31 kg, charge = -1.60x10-19C) and protons (mass = 1.67 x 10-27, charge = 1.60x10-19C).
            We then did a pair check. For homework, there is a worksheet with all sorts of electrostatic forces problems. 

2/23 qod

What does superposition mean?

--ch

Wednesday, February 22, 2012

2/22 Back

As we turned in our crazy coasters practice problems from the previous night, very few of us knew what a momentous day we had in store for ourselves. It was the end of a phase in our physics careers; the start of another. Mechanics were finished; electricity had just begun.
We embarked on this new journey by first discovering the reactions produced by a Van de Graaff generator. We learned about the belt that runs inside the generator that creates electricity and charges the sphere. We also learned about physics lab-partner marriages. With all due respect, I think Sonny and I will find our own respective spouses. After seeing electricity run through Miranda, Shachi, Kyle, Jack, Carlie and I, we set out to complete the Electricity Stuff worksheet that Mr. E had passed out to us. We learned a bar trick with rabbit fur, used tape to generate an electric charge, and watched Mr. E smash lifesavers in the dark room. We completed that worksheet with plenty of time left in class and turned it in to the second period folder. Pretty much everyone then got a jump start on their homework, which was a guided reading worksheet on 18.1-18.5. It is due today.

QOTD: Why do wintergreen lifesavers spark when you bite into them?


The lifesavers are made of crystalline sugars that break and release electrons into the atmosphere upon being bitten, or smashed, as the case may be. Then, all of the freed electrons search for a new home in the atmosphere. The newly-positive atoms of the mint, the nitrogen in the air, and the electrons from the mint collide in a way that produces a faint blue light in the right conditions.

2/22 qod

Why do wintergreen lifesavers spark when you bite into them?

--ch

Tuesday, February 21, 2012

02/21 Wheeler

Today was no ordinary day in honors physics. Of course, no day in honors physics is ordinary, but this one was particularly special. We tested our roller coasters today! I always get to blog about the exciting things like tests (my favorite!) and spirit days and fun experiments. I know everyone else is quite jealous of this. I am dearly sorry.

At the beginning of class, we put the finishing touches on our coasters (just another piece of duct tape can't hurt, right?) and conversed about our calculations, coming to the conclusion of where the golden hula hoop target should be placed on Main Street. The location of this hula hoop meant life or death for our grades on this project. You can imagine that Matt and I were extremely calm about this...Anyway, there were plenty of unique designs of coasters, and almost all of them landed in the hula hoop on the first try. Except my group. We were special. We were so special that we managed to hit the hula hoop on the third time, which is always a charm, as we all know.

After proving (or failing to prove) the worthiness of our roller coasters, we headed back to the physics room and turned in our calculations for our roller coaster. We then began on a worksheet titled "Roller Coaster Review," which is due tomorrow if you did not finish it in class, like me. Judging by the title, I still have no idea what the worksheet is about. I'm just kidding; the worksheet reviews determining force factors and necessary speeds for a circular loop on, of all things, a roller coaster.

I would like to suggest that we apply our wonderful knowledge of roller coasters by visiting Kings Island when it re-opens in the warmer weather.

On to the question of the day. Woohoo! Although, my confidence in myself for answering this question appropriately is a bit low after today's experiences. We determined the distance the hula hoop needed to be placed from the balcony by using the information we gained from the photogate timer and the small-scale set up of our project. We used the speed of the marble, the height of the balcony from Main Street, the approximate time it would take the marble to reach Main Street, and the small-scale distance the marble landed from the table. Oh, and we also used those good old kinematics equations (they just don't go away, do they?) and the energy equations.

I can't wait until next blog! Maybe I will get a test day...or an awesome experiment day!

2/21 qod

How did you calculate where to put the hula hoop?

--ch

Monday, February 20, 2012

2/16 Tuazon

Quick stuff to know:
- Turned in: Nothing
- Returned: Energy test
- Assignments made: Finish Crazy Coasters calculations (Plus working on your group's windmill or Rube Goldberg machine)


Detailed stuff:
I walked into my second class period on this fine February the 16th of the year 2012 thinking about how I was going to prepare for yet another gathering-info-to-write-my-blog-with session. Then I forgot all about it two seconds later.


No matter. My memory will serve me well.


So on that fine, fine day, after my short term memory threw out the thoughts of my blog, we picked up our Energy Test from our folders. 


We began the class period with Coats-Haan and Mr. Ebersole asking us what were some good ways and bad ways of measuring the exit velocity of the marble as it left our rollercoasters. Two good ways were to use one of the photogates around the room (which Coats-Haan shows us how to use) and to measure it using the 3rd kinematics equation and the distance that the marble travels from being ejected at table height until it hits the ground. (I detail both of the good methods in my answer to the QotD.) One of the bad ways included using timers because they would be unreliable due to the great amount of human error involved in stopping and starting the them. Using Ui + Ki = Uf + Kf could also be considered a bad way because even though it gives a ballpark exit velocity, it does not take friction into consideration. 


Afterwards, Mr. Ebersole dismissed us from our tables so we could continue working on our ever-so-innovative rollercoasters and so we could experimentally measure the exit velocity using the two good methods. 


Matt's group had to finish putting their through-the-cardboard rollercoaster together. It was actually beginning to look sort of bulky and intimidating with all the tubing and double cardboard panels everywhere. It was like a Franken-coaster. However, Coats-Haan and Mr. Ebersole did say that many other groups throughout the day were copying their raging through-the-cardboard design. Good for them, setting precedents and whatnot. 


Back at our overly duck-taped, one-loop wonder, Trevor, Chris, Aimee and I went straight for the photogate at the end of the room to measure our exit velocity. It took us a while, though. Sometimes, because the beginning of our track was so steep, the marble would not land on the track until a second or two later and the marble would have an usually slow exit velocity from not being able to pick up the full speed from the tubing. Much of our time was spent stacking and removing Chris' folders and trying to get the photogate to sense that the marble was passing through it. Late we realized that the marble was simply shooting out a little too high for the photogate to sense it, and we all mentally smacked ourselves in the faces. 


Measuring with the 3rd kinematics equation method was a little more eventful. We propped our rollercoaster board up on top of Mr. Ebersole's table back by the AP lab, and after we measured the height of the table (0.8 m), we had a great time trying to see if the marble would land in the same spot every time (this is not a necessary step to finding the exit velocity). After our initial marble release, Chris put his eraser approximately where the marble landed (about .9 m away in the x-direction from the end of the rollercoaster) and we continued putting the marble through the coaster to see how often the marble would land in the area around the eraser. 


To end the period, we relaxed and finished our final calculations on the Crazy Coasters worksheet. 


Note: For #13, when you use the 3rd kinematics equation, use a height of 4 m instead of the 4.6 m (a measurement which has been wrong for years, apparently). The time you get as your answer in #13 will be used in the 3rd kinematics equation as well for #14. 


Question of the Day
Q: How do you measure exit velocity with the photogate timer?  How do you measure it by projecting it off the table?


A: To measure exit velocity with the photogate timer, you take the diameter of the ball and divide it by the change in time from the moment the ball entered the photogate to the moment it left the photogate. 


To measure the exit velocity by projecting the ball off the table, you use the 3rd kinematics equation for the motion in the y-direction to solve for the time it takes to touch the ground. You then take the distance in the x-direction that the ball traveled and divide it by the time you found using the 3rd kinematics equation to get the exit velocity. 


End Blog.


(Not too shabby for not remembering it until now, eh?) 

Thursday, February 16, 2012

2/16 qod

How do you measure exit velocity with the photogate timer?  How do you measure it by projecting it off the table?

--ch

Wednesday, February 15, 2012

2/15 Tamayo

Question of the day. What is the normal force at the top of a roller coaster loop if you are just on the verge of falling off?
The normal force would be close to zero. The normal force is greatest at the bottom of the loop and least at the top of the loop. The motion of the car keeps it from falling down so if it were on the verge of falling off the normal force would be nearing zero, once the car detaches from the track the normal force from the track can no longer act on the car.
Coats-Haan was not here for second period today in Physics. Mr. Ebersole led us in today’s activities. We first turned in Desperado Redesign, if we didn’t turn it in on Tuesday. If we turned it in on Tuesday then, it was in our folders. We then looked at page 139-140 Crazy Coasters. This lab is completed with the people at our tables. This lab is quite exciting. First we had to complete questions 1-6 then we were able to start the building process. This lab consists of creating a rollercoaster for a marble. We then have to calculate where the marble will land. We worked on this for the entire day and we will have tomorrow as well. The coasters will be tested on Tuesday after the long weekend. Mr. Ebersole did warn us that if we leave the room with the marble then we will lose a lot of points on this lab for our group. This concludes our activities today in second period Physics.
Turned In: Desperado Redesign (if not turned in on Tuesday)
Got Back: Desperado Redesign (if turned in on Tuesday)
Homework: No homework!(Windmill Projects)

2/15 qod

What is the normal force at the top of a roller coaster loop if you are just on the verge of falling off?

--ch

Tuesday, February 14, 2012

2/14 qod

Why does a clothoid loop result in less g forces?

Happy Valentine's Day!

--ch

Monday, February 13, 2012

2/13 Shah

Today in 1960, France exploded its first atomic bomb on one of the most ecologically fragile places, the Sahara desert. However, in our Physics class, we started class by finishing the video, and then we changed gears into our lab manual. We worked on pages 131 onwards, which dealt with roller coasters. We discussed multiple errors in various structures and methods to prevent those errors, followed by a reading and questions to accompany it. There were a few math problems related to that which we worked on in the end. We were running out of time so Coats-Haan took over and quickly finished the problem since we were running out of time. Homework is to finish number 10 and 11 from that assignment. We had nothing to turn in from the weekend as we spend Friday watching the roller coaster video. However, in our folders we got our test review and lab report back. Question of the Day: the normal force at the top of a roller coaster, if the passengers are just at the verge of falling off, is equal to the gravitational force, and thus F=mg.

2/13 qod

 What is the normal force at the top of a roller coaster, if the passengers are just at the verge of falling off?

--ch

Sunday, February 12, 2012

2/12 Scheitlin

In physics class on Friday we watched a very interesting video on roller coasters. Before the video we were asked to fill out the before true/false questions on Extreme Machines Roller Coasters found on page 129 of your lab manual. The video took up the entire class time and Coats-Haan promised us that the video was rated PG, but I am not sure on that one. It was also hard not to laugh during the video, especially with the contagious laughter of Alexis. Overall it was a very relaxing class and if you did not turn in the worksheet on the video on Friday then you can turn it in on Monday, otherwise there is no homework due on Monday.

Question of the Day: Explain the g forces you experience on a roller coaster- well the g forces on roller coasters usually vary between +4 and -1/2. The more positive g's are experienced at the bottom of a drop.When accelerating downward you experience less positive g's which make you  feel weightless and when accelerating up a steep hill you will feel heavier than normal because of the extra positive g's.

Friday, February 10, 2012

Thursday, February 9, 2012

2/9 qod

Describe the types of energy you have as you go around a roller coaster loop.
--ch

Wednesday, February 8, 2012

2/08/2012 Nyaega

We began our wonderful Wednesday morning second period physics class by retrieving our Energy Practice Problems (which were also the previous nights homework) and using keys that were placed on our desks to check over our work. We were also given this time to work on our Energy test review guide. We were instructed to ask questions concerning, not only the review guide and energy practice problems, but on the whole unit in general  for that was the last time (before the test) that questions could be asked. Various questions were indeed asked, some coming from Emily, others from Ethan and many more. The purpose of today's class was to prepare for our test and not much else was done.

Question of the day: How does the height that a pendulum rises to relate to the maximum angle that it makes with the vertical?

The angle made when it's at its maximum determines the height by the fact that the height is equal to the length of the string - length * cos of the angle.

2/8 qod

How does the height that a pendulum rises to relate to the maximum angle that it makes with the vertical?

--ch

Tuesday, February 7, 2012

2/7 qod

Give an example of a conservation of energy problem that has spring potential, gravitational potential, and kinetic energy.

--ch

Monday, February 6, 2012

02/06 Miley

To begin our marvelous Monday we checked our homework from the weekend, which was pg. 192 #55-60. After Mr. Ebersole helped clear up any confusion from the homework and discussed Superbowl commercials with us we began the Spring POGIL. This POGIL can be found on pgs. 118 and 119 of the lab manual. This POGIL helped us in learning how springs do work and how to measure this. Because the POGIL took longer than expected, it became part of our homework in addition to pg. 193 #63-67, the Home Energy survey, and the lab report for Conservation of Energy with Hall’s Carriage due on Wednesday.

QOD: Why is the definition of “work = Force x Distance” not always true?
           
I believe it is not always true because more than one force, like resistance or friction or gravity, may be acting on the object and impact the amount of work being done. Though I am not sure this is correct I drew my conclusion from # 60 on the pg. 192 homework. 

2/6 qod

Why is the definition "work = force x distance" not always true?

--ch

Friday, February 3, 2012

2/3 qod

Explain how we derived the second equation for power from the first.

--ch

Thursday, February 2, 2012

leonow 2/2/12

Today, we started off class by going over the arduous 25 problem homework about conservation of energy.  Mrs. Coats-Haan praised our class for standing out among the other Honors Physics classes in work ethic, especially on our recent ticker tape lab.  Then we worked on a lab called the Conservation of Energy with Hall's Carriage.  It can be found on page 125 of the lab manual.  This lab report is due 2/8/12 and the only homework for tonight is to work on the online simulation due tomorrow as well as the home energy survey.

The answer to the question of the day is final kinetic and potential energy can equal zero when the height is zero and when the moving object moves across a surface with great friction, causing it to slow to a stop by the work done by friction. 

2/2 qod

Give an example of using the Ui+Ki+W=Uf+Kf equation where the right side would all be zero.

-ch

Wednesday, February 1, 2012

2/1 qod

Happy February! 
Give an example of when the work term in the conservation of energy would be positive and when it would be negative.
--ch