Monday April 21, 2008

Reviewed some of the WebAssign problems that gave people trouble.

Andrew demonstrated jumping into the air.
Students predicted what a graph of normal force vs time would look like for his jump.
Discussed these graphs. Used force plate to observe the actual force vs time.

Talked about man on bathroom scale in elevator problems.

Suppose you have a jar of flies on an electronic balance and all the flies are sitting on the bottom. How would the scale reading change if the flies took off and flew around the jar. Referred to finger in water demo - the scale reading would not change.

Demo with flying saucer on force plate - same reading when it is resting on plate as when it is hovering above it.

Gave time for students to ask questions one on one.

Test tomorrow.