Test: SHM and Waves

Today was your test covering simple harmonic motion and waves. If you missed this test, please make it up by Tuesday so I can give them back.

Pendulums and SHM

Today we used your lab results to get the equation for the period of a simple pendulum. We also watched a fun pendulum video and mentioned physical pendulums.

Notes: Pendulums

Here are the links for the videos we watched:

Harvard Natural Sciences Lecture Demonstrations: Pendulum Waves
Memo Akten: SHM #2 Excerpt
Somewhere in here we also talked about speed walking and pendulums, so here is a video of speed walkers.

Here is a great video that explains how patterns are made using a pendulum with different periods in different dimensions of motion: YouTube: Sand pendulums - Lissajous patterns - part one // Homemade Science with Bruce Yeany. The explanation of how they work starts at 4 minutes in.

Practice problems: p. 468 #34, 35, 39

Lab: Period of a Pendulum

Today we basically did the same lab as last week, except for a pendulum instead of a spring on a mass:

For any linear graphs you get, try to figure out what the slope represents. Also, don't displace the pendulum by more than 15 degrees.

If you were gone, there is a very nice pendulum simulation here: PhET Pendulum Lab. There is even a lovely photo gate timer that you can turn on that will measure one period for you. If you prefer a standard stopwatch, one will appear if you turn on "other tools."

No extra homework tonight; just get the lab totally finished.

Circles and SHM

Today we used circles to model simple harmonic motion, which gave us some equations for the position, velocity, and acceleration of an object undergoing SHM. We also talked about angular frequency.

Notes ended up on the board (below) and we used these sites to look at the motion:

UNSW School of Physics PhysClips: SHM Background Material

Teresa Martin Physics Flash Animations

If we had time we also watched this (just because it's cool).

Suggested homework is Chapter 13 (p. 467) #12, 18, 22. This was actually the wrong set, but by the time I realized that it was too late to change, so we're going with it. But next year...#18, 22, 28

Springs and Simple Harmonic Motion

Today we used the results from your lab to get an equation for the period of a mass on a spring. We also took a little bit of notes beyond that:

Notes: Simple Harmonic Motion

Suggested homework is a little half-sheet worksheet I made: HW: Period of a Mass/Spring System

Period of a Spring Lab

Today you completed a lab to determine what and how quantities affect the period of oscillation for a mass on a spring.

Lab: Finding T for a Mass on a Spring

No extra homework tonight, but this lab is due Wednesday.

We ended up with some hints on the board, so there is a picture of it below.

If you missed the lab or didn't get enough data at home, there is an online simulation here:

PhET Mass-Spring Lab

To use it you need to make sure the "friction" is set to zero, time is set to "real time" and the planet is "earth." Use the spring on the far right and change its k value by moving the "softness spring 3" slider. You will have to find the k for each "softness" level by hanging a known weight on the spring and measuring how far it stretches (tip: if you set the friction to "lots" for this part, it will keep the mass from bouncing and let you measure the stretch more easily). Then k = mg/x. Finally, you'll need more masses that the labelled ones provided, so I found the masses of the unlabeled colored masses for you: green = 70g, gold = 160g, red = 300g.

Wave Interference and Reflection

Today we talked about what happens when waves overlap or hit a barrier/change mediums.

Notes
Simulations:
Zona Land Education: Wave Interference I
Zona Land Education: Wave Interference II
Zona Land Education: Wave Interference III
PhET: Wave on a String

Homework: There is almost nothing to practice interference in the textbook, so your homework tonight is to play a game. Download the app Kerflux and get to at least level 30. Please note you do NOT have to pay anything for this game. If you do not have a device that can run Kerflux, that's okay too; I'm not actually checking this.

On Wednesday you will have a work day to prepare for your unit test.

Your unit test is on your next modular day. Below you will find a link to the practice test as well as a key.

SHM and Waves Test Practice

Solutions videos (note that the numbers of the problems have changed but the problems themselves have not):
#9
#10
#11
#12

Period of a Pendulum

Today we used your lab results to get the equation for the period of a simple pendulum. We also watched a fun pendulum video and mentioned physical pendulums.

Notes: Pendulums

Here are the links for the videos we watched:

Harvard Natural Sciences Lecture Demonstrations: Pendulum Waves
Memo Akten: SHM #2 Excerpt
Somewhere in here we also talked about speed walking and pendulums, so here is a video of speed walkers.

Here is a great video that explains how patterns are made using a pendulum with different periods in different dimensions of motion: YouTube: Sand pendulums - Lissajous patterns - part one // Homemade Science with Bruce Yeany. The explanation of how they work starts at 4 minutes in.

Homework is Ch. 13 (p. 468) #34, 35, 39

Tomorrow is a half day!

SHM Practice Problems

Today you worked on practice problems while I was in meetings elsewhere.

Ch. 13 Conceptual (p.465) #1, 2 + Problems (p. 467) #19, 21, 24, 25, 28

Anything you don't finish is homework, and we will go over your period of a pendulum labs tomorrow. Please have them done.

Lab: Period of a Pendulum

Today we basically did the same lab as last week, except for a pendulum instead of a spring on a mass:



For any linear graphs you get, try to figure out what the slope represents. Also, don't displace the pendulum by more than 20 degrees.

If you were gone, there is a very nice pendulum simulation here: PhET Pendulum Lab. There is even a lovely photo gate timer that you can turn on that will measure one period for you. If you prefer a standard stopwatch, one will appear if you turn on "other tools."

No extra homework tonight; just get the lab totally finished.

Circles and SHM

Today we used circles to model simple harmonic motion, which gave us some equations for the position, velocity, and acceleration of an object undergoing SHM. We also talked about angular frequency.

Notes ended up on the board (below) and we used these sites to look at the motion:

UNSW School of Physics PhysClips: SHM Background Material

Teresa Martin Physics Flash Animations

If we had time we also watched this (just because it's cool).

Homework is Chapter 13 (p. 467) #12, 18, 22

Springs and Simple Harmonic Motion

Today we used the results from your lab to get an equation for the period of a mass on a spring. We also took a little bit of notes beyond that:

Notes: Simple Harmonic Motion

Homework is a little half-sheet worksheet I made: HW: Period of a Mass/Spring System

Lab: Period of a Spring

Today you completed a lab to determine what and how quantities affect the period of oscillation for a mass on a spring.

Lab: Finding T for a Mass on a Spring

No extra homework tonight, but this lab is due Wednesday.

We ended up with some hints on the board, so there is a picture of it below.

If you missed the lab or didn't get enough data at home, there is an online simulation here:

PhET Mass-Spring Lab

To use it you need to make sure the "friction" is set to zero, time is set to "real time" and the planet is "earth." Use the spring on the far right and change its k value by moving the "softness spring 3" slider. You will have to find the k for each "softness" level by hanging a known weight on the spring and measuring how far it stretches (tip: if you set the friction to "lots" for this part, it will keep the mass from bouncing and let you measure the stretch more easily). Then k = mg/x. Finally, you'll need more masses that the labelled ones provided, so I found the masses of the unlabeled colored masses for you: green = 70g, gold = 160g, red = 300g.

Period of a Pendulum

Today we used your lab results to get the equation for the period of a simple pendulum. We also watched a fun pendulum video and mentioned physical pendulums.

Notes: Pendulums

In case you can't access the Powerpoint, here are the links for the videos we watched:


Harvard Natural Sciences Lecture Demonstrations: Pendulum Waves
Memo Akten: SHM #2 Excerpt
Somewhere in here we also talked about speed walking and pendulums, so here is a video of speed walkers.

Homework is Ch. 13 (p. 468) #34, 35, 39

Lab: Period of a Pendulum

Today we basically did the same lab as last week, except for a pendulum instead of a spring on a mass:



For any linear graphs you get, try to figure out what the slope represents. Also, don't displace the pendulum by more than 20 degrees.

If you were gone, there is a very nice pendulum simulation here: PhET Pendulum Lab. There is even a lovely photo gate timer that you can turn on that will measure one period for you. If you prefer a standard stopwatch, one will appear if you turn on "other tools."

No extra homework tonight; just get the lab totally finished.

SHM Practice Problems

Today you worked on practice problems while I checked your labs from earlier in the week. These are due next class:

Ch. 13 Conceptual (p.465) #1, 2 + Problems (p. 467) #19, 21, 24, 25, 28

Bring your lab notebook next class! We're doing ANOTHER LAB!

Circles and SHM

Today we used circles to model simple harmonic motion, which gave us some equations for the position, velocity, and acceleration of an object undergoing SHM. We also talked about angular frequency.

Notes ended up on the board (below) and we used these sites to look at the motion:

UNSW School of Physics PhysClips: SHM Background Material

Teresa Martin Physics Flash Animations

If we had time we also watched this (just because it's cool).

Homework is Chapter 13 (p. 467) #12, 18, 22

Springs and Simple Harmonic Motion

Today we used the results from your lab to get an equation for the period of a mass on a spring. We also took a little bit of notes beyond that:

Notes: Simple Harmonic Motion

Homework is a little half-sheet worksheet I made: 2/7 HW (ignore the wrong date on this PDF scan).

Lab: Period of a Mass on a Spring

Today you completed a lab to determine what and how quantities affect the period of oscillation for a mass on a spring.

Lab: Finding T for a Mass on a Spring

No extra homework tonight, but this lab is due Wednesday.

We ended up with some hints on the board, so there is a picture of it below.

If you missed the lab or didn't get enough data at home, there is an online simulation here:

PhET Mass-Spring Lab

To use it you need to make sure the "friction" is set to zero, time is set to "real time" and the planet is "earth." Use the spring on the far right and change its k value by moving the "softness spring 3" slider. You will have to find the k for each "softness" level by hanging a known weight on the spring and measuring how far it stretches (tip: if you set the friction to "lots" for this part, it will keep the mass from bouncing and let you measure the stretch more easily). Then k = mg/x. Finally, you'll need more masses that the labelled ones provided, so I found the masses of the unlabeled colored masses for you: green = 70g, gold = 160g, red = 300g.

Spring Intro Lab

Today we derived Hooke's Law with a little intro lab:

Spring Intro Lab

The lab is due tomorrow.