Friday, April 17, 2009 - Block 2

Collected RA 4.5

Hung pictures on board and students voted on Horse Sense
Went over RA 4.4

Talked about what force a bathroom scale actually reads (It reads the reaction to normal force of person on scale. Did examples of bathroom scale in elevator showing how you draw the free body diagram, choose the direction of acceleration to be positive, write down Newton's Law and solve for the normal force (which has the same magnitude as the scale reading).

Asked students to predict what a Force vs Time diagram would be for someone stepping on the force plate, jumping up and coming down, and then stepping off. After discussion the predictions on board, students did demo.

On Applying Newton's Laws worksheet, asked students to do the blocks problem. Explained it in detail on the board.

Homework, do circled problems 3-24 for Monday. Gave students 15 minutes in class to work on them. Test is Thursday.