Wednesday, November 12, 2008 - Blocks 1 and 3

Go over test.

Force plate demo: Ask students to predict what the Force vs Time graph would look like for someone jumping up into the air. Sketch predictions on whiteboard.

Do demo - discuss.

Go over elevator problems on whiteboard.

Show inclined plane problem first with no friction and then with friction. Show how to determine angles and use problem solving strategy.

Inclined plane cart demo: Ask students to predict what the displacement vs time, velocity vs time, and acceleration vs time graphs would look like for cart on track with motion sensor. Do they predict the same slope (acceleration) for the velocity vs time graph up and down? Show that the slopes are different because on the way up friction is opposite the component of weight but on the way down the friction force is along the component of weight. The net forces are different in both cases.

Show how we can actually calculate the coefficient of friction for the rolling cart.

Hand out Newton's Laws Practice Problems and Applying Newton's Laws problem sets. Assign problems 8,9,10,11 on Practice Problem sheet. Ask in particular that they do the problem on getting the car out of the mud. Do this problem on board first thing Thursday.