How did we use marshmallows to measure the speed of light?
--ch
Wednesday, March 28, 2012
Friday, March 23, 2012
Thursday, March 22, 2012
2/22 Shah
Turned in
Class activities
Today we continued the sound lab marathon from yesterday. Everyone scrambled in attempt to finish the lab today; however, most (if not all) of us did not finish it and so we will have the beginning of class tomorrow to begin it. Interestingly enough, while working on the part with the mic, my group forgot that we had a recorder at our convenience to create the sounds. We took the fun route. Or at least Ethan did. Ethan sang/talked/made noise into the mic instead. Yes, we’re just creative. J Not really, we’re just forgetful.
QOD
Ironic enough, the sound barrier section is the section my group still has to complete. So I’m not 100% sure, but I think traveling through carbon dioxide would slow the speed of sound.
Assignments
Tonight we have no homework in Honors Physics. J However, given that we have a sound test next Monday and the exam next Friday, it would be advisable to start the review packets. Class activities
Today we continued the sound lab marathon from yesterday. Everyone scrambled in attempt to finish the lab today; however, most (if not all) of us did not finish it and so we will have the beginning of class tomorrow to begin it. Interestingly enough, while working on the part with the mic, my group forgot that we had a recorder at our convenience to create the sounds. We took the fun route. Or at least Ethan did. Ethan sang/talked/made noise into the mic instead. Yes, we’re just creative. J Not really, we’re just forgetful.
QOD
Ironic enough, the sound barrier section is the section my group still has to complete. So I’m not 100% sure, but I think traveling through carbon dioxide would slow the speed of sound.
Wednesday, March 21, 2012
Tuesday, March 20, 2012
03/20 Wheeler
Today, March 20th, is a rather exciting blog day for me. Why? Well, first off, I always find something cool or exciting about the blog. Second, this is only my second blog on a non-test day! So, I get to explain the fantastic physics we learned today, not just describe how we scribbled with pencils and punched numbers into the calculator the entire period, all the while stressing if number seventeen is correct. For Coats-Haan's sake, I hope our test-taking doesn't look as boring as the sophomores during OGT week.
We turned in the Shockwaves Worksheet (if you did not finish it yesterday) and we checked page 507, numbers 70-76 in our physics book (which could stand to lose some weight, I might add). Coats-Haan piped in at this time to remind Chris Roseblossom he needs to get off the streak of not doing homework, reminding him that he was one of the smartest, laziest kids she knows. I agree with that statement. Also, keep in mind that our exams are next week! So, working on the 3rd quarter exam review is not a bad idea.
I rather liked today's notes. There were only twelve slides, I believe, either way not enough to make my hand hurt. We learned the difference between intensity and loudness. Intensity is the rate at which the sound energy flows through a unit area normal to the direction of propagation. Loudness (or volume, as the slides pointed out) depends on an auditory sensation in the consciousness of a human listener and isn't quantifiable.
Okay, so here are a few more handy equations we learned in class today. Try to make some room in your brain for a couple more, okay? We are three fourths of the way through the year. We can do this!
Intensity = Power/Area
Or, the shorter version (aka Chris Roseblossom's version), I = P/A
P is in watts, A is in square meters, and I is in watts per square meter.
The normal area is the surface area of a sphere, 4 times pi times radius squared (hello, old friend geometry!).
B = 10 log (I/Io)
Io = 10-12 watts per meter squared
B is the relative intensity in decibels
Recalling those log properties we learned (again) a few months ago in honors pre-calc might also do you some good.
For homework, we have to complete the pair check (if not finished in class) and do two worksheets, one titled "Loudness and Intensity Homework" (I would have never guessed) and the other "Detecting Decibels/I've Got Your Frequency."
And finally, to answer the question of the day. Because of the large range of intensities over which the ear is sensitive, we use the logarithmic scale.
We turned in the Shockwaves Worksheet (if you did not finish it yesterday) and we checked page 507, numbers 70-76 in our physics book (which could stand to lose some weight, I might add). Coats-Haan piped in at this time to remind Chris Roseblossom he needs to get off the streak of not doing homework, reminding him that he was one of the smartest, laziest kids she knows. I agree with that statement. Also, keep in mind that our exams are next week! So, working on the 3rd quarter exam review is not a bad idea.
I rather liked today's notes. There were only twelve slides, I believe, either way not enough to make my hand hurt. We learned the difference between intensity and loudness. Intensity is the rate at which the sound energy flows through a unit area normal to the direction of propagation. Loudness (or volume, as the slides pointed out) depends on an auditory sensation in the consciousness of a human listener and isn't quantifiable.
Okay, so here are a few more handy equations we learned in class today. Try to make some room in your brain for a couple more, okay? We are three fourths of the way through the year. We can do this!
Intensity = Power/Area
Or, the shorter version (aka Chris Roseblossom's version), I = P/A
P is in watts, A is in square meters, and I is in watts per square meter.
The normal area is the surface area of a sphere, 4 times pi times radius squared (hello, old friend geometry!).
B = 10 log (I/Io)
Io = 10-12 watts per meter squared
B is the relative intensity in decibels
Recalling those log properties we learned (again) a few months ago in honors pre-calc might also do you some good.
For homework, we have to complete the pair check (if not finished in class) and do two worksheets, one titled "Loudness and Intensity Homework" (I would have never guessed) and the other "Detecting Decibels/I've Got Your Frequency."
And finally, to answer the question of the day. Because of the large range of intensities over which the ear is sensitive, we use the logarithmic scale.
Monday, March 19, 2012
03/19 Tuazon
Turned in:
Doppler Effect Simulation
16.9 and 16.10 Guided Reading
Returned:
Sound Reading Questions
Class activities:
Doppler Effect Notes
Shockwaves Worksheet
Homework:
Shockwaves Worksheet (if not finished in class)
Honors Physics 3rd Quarter Test Review (begin working on this)
P. 507, #70-76 in our textbook
Study for sound test on Monday
-------
With my Doppler Effect Simulation and Guided Reading already turned in before school started (I had to come in early because my computer would not run the simulation) and my Sound Reading Questions already picked up out of my folder, I went up to the board to write down the honors physics homework really quick. To my side, I could hear Jeff and a few other people complaining about something Mr. Ebersole said, and as I tuned in, I heard great news that we had a sound test on Monday.
Yeah––the first real test we would have in weeks would be on exam week.
I joined in with the petty whining for a while, with Mr. Ebersole telling us to calm down, before returning back to my seat and watching as Mr. Ebersole prepared to show us some equipment to demonstrate the Doppler Effect.
One thing I remember them comparing the two pieces of equipment they used. One was a really expensive metal rod with a tone box attached to the end of it that could probably decapitate Mr. Ebersole if he did not move out of the way, while the other one was a rubber tube that Ms. Grote bought for $1 at a toy store that did not even need the tone box at the end to demonstrate the same thing. Coats-Haan said something about how East is obviously superior because of this.
Anyway, for the demonstration, Mr. Ebersole waved both sounding objects around his head, and the pitch became higher as the source moved closer to us, and the pitch lowered moving away from us. This is because of the source's velocity.
Then we went off to take notes, which Mr. Ebersole was really excited about ("Oh my gosh, we get to skip a ton of slides today! We've just made this powerpoint go from 19 slides to 6 slides!").
We learned that the general form for the Doppler Effect is:
fo = fs (1 ± vo/v) / (1 ∓ vs/v)
The variables for this are:
fo = frequency observed
fs = frequency of source
vo = velocity of observer
vs = velocity of source
v = speed of sound
Note: The upper signs of the + or - sections of the equations are used when the observer or source is going toward the other, and the bottom signs of the + or - sections of the equations are used when the observer or source is going away from the other.
We also did example problem #6 and #7, in which all you have to do is plug in the known values to find the frequency of the source and the frequency observed, respectively. The answer for #6 is 490 Hz, and the answer for #7 is 410 Hz.
Additional note from questions other students asked in class:
- Depending on direction the observer and source are going in relation to each other, you may use both top signs, both bottom signs, or one of each sign in the equation.
- If either the observer or source is stationary, their respective top or bottom portion of the equation will end up being zero.
- As long as the speed of the observer and source stay the same, the frequency observed will be the same, even if one catches up with the other. However, at the point when the observer is on the opposite side of the source, the frequency observed will be different (yet still consistent on that side of the source).
Finally, we wrapped our our period working on a Shockwaves Worksheet.
This is what my table concluded (We also got 100% on our worksheet according to HAC, so this information should be accurate)
- As speed increases, the angle of the spacecraft to the shockwave gets narrower
- The distance of the the spacecraft goes divided by the distance the shockwave goes (its radius) is the relative speed of the spacecraft to the speed of sound.
For example: If the spacecraft moves 8 cm, and the shockwave has a radius of 2 cm, 8 cm divided by 2 cm is 4, meaning the spacecraft is going 4 times the speed of sound.
Wow, that was a lot of information. Feel free to ask for clarification.
-------
Question of the Day:
Describe a situation where both the signs are positive in the Doppler Effect Equation.
--ch
Answer: A situation in which the observer is going toward the source and the source is going away from the observer would result in both signs being positive in the Doppler Effect Equation. Such a situation may be Trevor moving toward Chris, trying to get him to work on stuff for our Rube Goldberg Machine, while Chris is covering his ears, making a really annoying sound to block out Trevor's requests, and running away.
Doppler Effect Simulation
16.9 and 16.10 Guided Reading
Returned:
Sound Reading Questions
Class activities:
Doppler Effect Notes
Shockwaves Worksheet
Homework:
Shockwaves Worksheet (if not finished in class)
Honors Physics 3rd Quarter Test Review (begin working on this)
P. 507, #70-76 in our textbook
Study for sound test on Monday
-------
With my Doppler Effect Simulation and Guided Reading already turned in before school started (I had to come in early because my computer would not run the simulation) and my Sound Reading Questions already picked up out of my folder, I went up to the board to write down the honors physics homework really quick. To my side, I could hear Jeff and a few other people complaining about something Mr. Ebersole said, and as I tuned in, I heard great news that we had a sound test on Monday.
Yeah––the first real test we would have in weeks would be on exam week.
I joined in with the petty whining for a while, with Mr. Ebersole telling us to calm down, before returning back to my seat and watching as Mr. Ebersole prepared to show us some equipment to demonstrate the Doppler Effect.
One thing I remember them comparing the two pieces of equipment they used. One was a really expensive metal rod with a tone box attached to the end of it that could probably decapitate Mr. Ebersole if he did not move out of the way, while the other one was a rubber tube that Ms. Grote bought for $1 at a toy store that did not even need the tone box at the end to demonstrate the same thing. Coats-Haan said something about how East is obviously superior because of this.
Anyway, for the demonstration, Mr. Ebersole waved both sounding objects around his head, and the pitch became higher as the source moved closer to us, and the pitch lowered moving away from us. This is because of the source's velocity.
Then we went off to take notes, which Mr. Ebersole was really excited about ("Oh my gosh, we get to skip a ton of slides today! We've just made this powerpoint go from 19 slides to 6 slides!").
We learned that the general form for the Doppler Effect is:
fo = fs (1 ± vo/v) / (1 ∓ vs/v)
The variables for this are:
fo = frequency observed
fs = frequency of source
vo = velocity of observer
vs = velocity of source
v = speed of sound
Note: The upper signs of the + or - sections of the equations are used when the observer or source is going toward the other, and the bottom signs of the + or - sections of the equations are used when the observer or source is going away from the other.
We also did example problem #6 and #7, in which all you have to do is plug in the known values to find the frequency of the source and the frequency observed, respectively. The answer for #6 is 490 Hz, and the answer for #7 is 410 Hz.
Additional note from questions other students asked in class:
- Depending on direction the observer and source are going in relation to each other, you may use both top signs, both bottom signs, or one of each sign in the equation.
- If either the observer or source is stationary, their respective top or bottom portion of the equation will end up being zero.
- As long as the speed of the observer and source stay the same, the frequency observed will be the same, even if one catches up with the other. However, at the point when the observer is on the opposite side of the source, the frequency observed will be different (yet still consistent on that side of the source).
Finally, we wrapped our our period working on a Shockwaves Worksheet.
This is what my table concluded (We also got 100% on our worksheet according to HAC, so this information should be accurate)
- As speed increases, the angle of the spacecraft to the shockwave gets narrower
- The distance of the the spacecraft goes divided by the distance the shockwave goes (its radius) is the relative speed of the spacecraft to the speed of sound.
For example: If the spacecraft moves 8 cm, and the shockwave has a radius of 2 cm, 8 cm divided by 2 cm is 4, meaning the spacecraft is going 4 times the speed of sound.
Wow, that was a lot of information. Feel free to ask for clarification.
-------
Question of the Day:
Describe a situation where both the signs are positive in the Doppler Effect Equation.
--ch
Answer: A situation in which the observer is going toward the source and the source is going away from the observer would result in both signs being positive in the Doppler Effect Equation. Such a situation may be Trevor moving toward Chris, trying to get him to work on stuff for our Rube Goldberg Machine, while Chris is covering his ears, making a really annoying sound to block out Trevor's requests, and running away.
3/19 qod
Describe a situation where both the signs are positive in the Doppler effect equation.
--ch
--ch
Friday, March 16, 2012
Tuesday, March 13, 2012
Friday, March 9, 2012
3/9 qod
What do you think were some of the biggest barriers to making the windmills lift more weight?
--ch
--ch
Thursday, March 8, 2012
Wednesday, March 7, 2012
Miley 3/7
To begin the class period, Mr. Ebersole reminded us of all the upcoming things and assignments due: Section 4 Lab and Homework are due tomorrow (3/8), Windmills on Friday (3/9), and our third electricity quiz tomorrow. We then continued by learning about Ohm’s Law and Equivalent resistance. Ohm’s law is V=iR and helps prove that resistance and current are inversely proportional. Equivalent resistance is when the resistance of the single resistor would produce the same effect as what is produced by the network. Both of these concepts are the math used to prove what we have been learning in the circuit labs. After taking our notes and finishing the example problems, Mr. Ebersole handed out a circuit worksheet that review what we have previous learned and the new concepts learned today. This worksheet is also due tomorrow (3/8). DON’T FORGET: 3 DAYS TILL WINDMILLS!
QOD: Use the mathematical equations for finding equivalent resistance to explain the results you observed for bulb brightness in the lab.
As seen in the equations for resistance equivalence, series and parallel circuits vary in how they are calculated. For a series, you just add the resistances together. And for a parallel circuit, you add the reciprocals for each resistor. As we’ve seen in the labs, the parallel circuits provide more pathways for the current to travel through, which can help decrease the resistance. In a series, one pathway is used which can sometimes cause more resistance. When executing the equations with actual problems, we can see that these ideas hold true. With less resistance the bulb can be brighter, as we’ve seen in parallel circuits and with more resistance the bulb may be dimmer, as seen in series. Though I’m confident with this answer, I’m not 100% sure that I’m correct.
3/8 qod
Use the mathematical equations for finding equivalent resistance to explain the results you observed for bulb brightness in the lab.
--ch
--ch
Tuesday, March 6, 2012
Monday, March 5, 2012
leonow 3/5
We continued working on our circuit lab. Section 3 was to be completed by the end of the period today and the homework was assigned for tomorrow. If you don't finish section 3, you may use some time at the beginning of the period tomorrow. The lab, including section 4, is to be done no later than Wednesday. Don't forget, the windmill/Rube Goldberg machine is due Friday and they can be brought in before school any day this week.
The answer to the question of the day is when more bulbs are added in parallel, the total resistance increases and current is allowed to flow more freely, indicated by the increased brightness of the bulbs. On the other hand, when more bulbs are added in series, the total resistance decreases and the current moves slower.
The answer to the question of the day is when more bulbs are added in parallel, the total resistance increases and current is allowed to flow more freely, indicated by the increased brightness of the bulbs. On the other hand, when more bulbs are added in series, the total resistance decreases and the current moves slower.
3/5 qod
If you add bulbs in parallel, what happens to resistance and flow through the battery?
If you add bulbs in series, what happens to resistance and flow through the battery?
--ch
If you add bulbs in series, what happens to resistance and flow through the battery?
--ch
Friday, March 2, 2012
3/2 qod
You have a circuit with multiple switches and bulbs. You are asked to rank the bulbs in all possible switch positions. Please describe how you should report your answer.
-ch
-ch
Thursday, March 1, 2012
3/1 qod
There are two circuits. One circuit has two bulbs in series. The other circuit has two bulbs in parallel. Which circuit has the brighter bulbs? Explain why.
--ch
--ch
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