Tuesday and Wednesday, 11/25 and 11/26

For two days we will be exploring the physics of Hollywood. What physics concepts do movies consistently get wrong? What do they get right?

Monday, 11/24: Going Over Test 3

We took today to go over Test 3, which we took last Tuesday. You will see these questions again on the final, so please review the answers frequently over the next month.

Due 11/24: HW: Temperature and Heat

Please answer these questions thoroghly on your own sheet of paper.

1. Why is it impossible to have a temperature lower than -273 degrees Celcius?
2. What is the difference between temperature and heat?

Friday, 11/21: Heat

Heat is energy that transfers from one object to another because of a temperature difference between the objects. Heat always moves from a higher temperature to a lower temperature naturally.

Thursday, 11/20: Temperature

Today we did a series of activities to explore what temperature measures. Basically, temperature measures the average kinetic energy of the particles that make up an object.

Wednesday, 11/19: Mechanics Post-Test

Today we are taking a post-test for mechanics. We took this same test as a pre-test back in August. Missing it or doing poorly will not harm your grade, but doing well will get you extra credit, so do your best!

Tuesday, 11/18: Test 3!

Test 3! If you miss this, you need to make it up by the end of the week; I want to have it graded and back to you next week.

Monday, 11/17: Test 3 Review

This is your day to review for the test. You can work on the review, discuss it with each other, ask me questions, make your note card, whatever! The review can be found in the previous post.

Friday, 11/14: Universal Gravitation (per 1, 4-6) OR Angular Momentum (per 3)

Look back at the posts for this week to get descriptions for these two lessons.

Test 3 Review

Test 3 will be on Tuesday, November 18. The review can be found at:

http://docs.google.com/Doc?id=dccgmhcd_22grn6hmw2

Thursday, 11/13: Orbits and Microgravity (p. 1, 4-6) or Universal Gravitation and its Consequences (per 3)

Another split lesson day. For the Universal Gravitation lesson, we go over the Law of Universal Gravitation:

F_G = (Gm₁m₂)/r²

We also talk about some of the consequences of this law, such as ocean tides and why you can't survive going into a black hole.

Wednesday, 11/12: Symmetry

Today we are talking about symmetry and making paper snowflakes. I know this seems like a silly thing to do in a physics class, but symmetry is actually very important in this field. One of the first things you should do when solving a physics problem is ask yourself, is there any symmetry here? It can save you a great deal of time and effort.

Snowflakes!
http://snowflakes.barkleyus.com/

Monday, 11/10: Angular Momentum (per 1, 4-6) or Orbits and Microgravity (per 3)

Periods 1 and 4-5 looked at the conservation of angular momentum and its implications. Period 3 will have that lesson on Friday; today they looked at why things orbit and why astronauts seem to be "weightless" in space.

Friday, 11/7: Center of Mass and Toppling

Basically, if the center of mass of an object is above (or below for hanging objects) a support, it is fine. If the center of mass is not above the support or base of the object, the object will topple. Today we played with several examples of balance and toppling, including trying to tough our toes when standing up against a wall. Fun :)

Thursday, 11/6: Center of Mass

Yay, the class notebook came back! It'll take me awhile, but I will get notes written in the notebook and pictures of them here. Anyway, today we introduced center of mass. Tomorrow, center of mass and how it relates to balance and toppling.

Wednesday, 11/5: Centrifugal Force

Today we talked about what centrifugal force is and where it comes from. Remember, centrifugal force isn't a true force, but a consequence of a rotating reference frame. It always points away from the center of the circle.

We saw a demonstration of centrifugal force and watched some clips from 2001: A Space Odyssey to see examples of the use of centrifugal force as artificial gravity.

Comic by xkcd.com

Tuesday, 11/4: Relative Velocity and Frames of Reference

Today's topics are relative velocity and frames of reference. Partial notes are below.

Monday, 11/3: Centripetal Acceleration and Centripetal Force

Today we introduced centripetal acceleration and centripetal force. The lead-in to these topics was the majority of the class, and cannot be reproduced here, but I can give you the final equations for these quantities:

Centripetal acceleration:

a_c = v²/r

Centripetal force:

F_c = mv²/r

"Centripetal" means "center seeking" and refers to the fact that these vector quantities always point to the center of the circle.