ANNOUNCEMENTS

Friction Lab Class Conclusions

• Force of friction increases with mass

• Force of friction is different with different surfaces (rubber was the highest, partially b/c it conforms to surfaces)

• Higher speed seemed to increase Force of friction slightly, but the relationship was not clear

• It takes more force to start something moving than to keep something moving: Force of moving friction is lower

• Smoothness is not related to Force of friction (rubber is smooth but has high friction, for example)

• Surface area increased Force of friction, but not significantly

• Slope increased the towing force, but not due to increased friction (b/c you were fighting gravity more directly)

Here are a couple of excellent reading memos (emails about the reading).  Notice how they pose questions and summarize what they think they understand.  Hopefully they will answer the questions they pose in future emails or in class.

>>> JENNA ATHA 09/20/02 12:41PM >>>

Hello Jenna.

I read the sections in physics and this is what I think:

I thought that the reading was nice and simple, and for the most part easy to understand. Most of the stuff I already knew from previous science classes. I thought it was interesting that everything moves even if it appears to be at rest. "Motion is everywhere." That part was a bit confusing with the relative to this and relative to that, but the book did a pretty good job of explaining it. The part about the difference between speed and velocity was also interesting. I always considered them to be the same thing, but speed is d/t, and velocity is related to direction. It wasn't very long so I don't have too much to say. I think that is it. I hope I didn't bore you too much!

Sara Yell

MY E-MAIL TO HER!

Hey ~

Here we go again for the second time. What did you think of the Physics reading in chapter two not three? I was glad it was kind of short, it was easier to read over and comprehend that way. I didn't know that speed and velocity were used different in Physics. Could we find velocity in the Buggie lab because it is going towards or away? This lab had no constant velocity because the cars kind of curve to the right. Do you know what the difference between rate and velocity is? Just curious because I don't.  Well, overall I think I knew most of the information in this chapter. Thanks for listening sorry I couldn't get it to you sooner my school e-mail won't work. See you in class!

Toodles,

Jenna Atha

Current Physics A Links

Read the essay "On Being the Right Size"

Visit the textbook web site

1st QUARTER HOMEWORK

What have we studied so far?

Study Tips

RUBRICS for grading  LOOK HERE FOR INFO ABOUT LAB REPORTS!

Examples of student quick writes

Check out some of the pictures from our rocket project (past years)

Physics A is a modeling class.  Find out more about modeling at

• Physics Classwork, Handouts, & Homework
• Physics Quizzes & Tests
• Physics Labs