## ReAssessment Notes

Just a few quick reminders:

- If you want to submit a reassessment, you must submit
*something*within 2 weeks of the original assessment. After that, if you still don’t understand the material, you can re-reassess. - Peer review. I said you need to have your screen cast reviewed by at least two other students. I am not going to check this, but it is still a requirement. I don’t want you sending me something that you haven’t had someone else go over also. Trust me, this is good for you.
- If you have technical difficulties with screen casts, ask me for help. If you ask me for help one hour before the screen cast is due, I will talk really slowly.
- VPython. I still haven’t decided how to assess the vpython things. They will be optional – in that your scores on vpython items will replace your other lowest scored standards. For now, just pick some program to show a screen cast of – hopefully you will show a vpython program that can demonstrate your understanding.

## Approximation for constant gravitational field

Here is a post you might like. It is an analysis of some gravitational wells.

http://blog-admin.wired.com/wiredscience/2010/01/xkcd-and-gravity-wells/

Yes, I know. We haven’t looked at potential energy yet. However, this does show how near the surface of the Earth the gravitational force is essentially constant. Sorry, I thought I had a post that did the same thing with forces, but I was wrong.

## An example of the momentum principle

This is very similar to the problems in the chapter 2 homework.

## Quick Intro to the Momentum Principle

Maybe this is useful, maybe not.

## Equations for Chapter 2

For Chapter 2, I would expect that you would know:

- The definition of average velocity
- The definition of momentum
- The momentum principle

I will give you the following equations (along with any constants you might need):

## Regarding VPython Standards

Here is what I am thinking: VPython is super important (well, numerical calculations) for all fields. However, since we don’t have computers in class I think someone could claim these standards are unfair. With this in mind I will make the following rule regarding the VPython Standards:

- It is highly recommended that you work on the VPython standards.
- I will even give a couple of questions in class regarding VPython standards.
- At the end of the semester, I will replace any of your lowest standards with VPython scores that are higher. So, say you do terrible on standard 1.3 and you only scored a 2/5. You did a VPython standard with a score of 4/5. I would replace the 2 with a 4 at the end of the semester.