9-28, today in class

HMWK tonight (see yesterday's post) Band people!  Take your test:  Tomorrow in class, Before school Friday (let me know if you plan to, so I can be here plenty early), or before/after school on Monday.
Exam 2: motion is Friday for everyone else. 

Today we did an exercise of explaining what was happening in graphs (above) verbally, then making (sketching) different graphs (velocity-time) based on what they would look like to represent the same motion.
You can use your notes on these graphs and your sketches from today to help you work on the practice WS from yesterday.
All classes got to see how to work on the optional assignments on my webpage, and I showed some classes that I had put the online textbook access code on our class EDLINE page.

Afterward, I showed different ways to solve for acceleration from your lab data:
1. use the: delta x = 1/2 a t ^2 equation and solve for acceleration after inserting your change in position and time.
 2. From a position - time graph, compare the slope at the start (0 m/s) with the slope between the last points (___ cm/s) with time from start to the mid point of the last two points and use the:  a = delta v / t  equation to solve for acceleration.
3. Make a position time^2 graph and (double) the slope of the line.  This is acceleration.
4. Make a velocity time graph and find the slope.  This is acceleration.  (this method is the easiest, but very few people chose it for some reason??)