Today in class, we began with our daily ipad activities followed by the postgame review:
1. Scalar quantity (magnitude) - mass(kg) & energy(J) vs. vector quantity (magnitude + direction) aka velocity & momentum
+ = right/up, - = down/left
2. collisions A. sketch; B. analyze; C. Scalar: KE=1/2mv(squared); vector: P = mv
3. %lost = total after - total before/total before
Big Ideas:
Elastic collisions conserve more Energy than inelastic collisions
Momentum is conserved in all collisions (total P before = total P after)
Momentum is the best way of analyzing collisions
Impulse
J = P(final) - P (initial)
impulse should be equal + opposite
momentum total - same before + after
any lost by one cart should be gained by another
impulse = this gain or loss
impulse for whole system = 0
conservation of momentum:
-any gain in momentum ...something else must lose momentum in a system
Real world connection:
If a clumsy student were to drop a textbook and a basketball out a window, he would see that they each had the same momentum right before they hit the ground. In addition, he would observe that the basketball had a greater impulse because its change in momentum is higher due to its elasticity.
No comments:
Post a Comment