Warm-Up Exercise for lecture 15

Due 8:00 am, Tues, 20 Oct 2009

Physics 105, Fall 2009

Moment of inertia is biggest for:
compact objects
objects that are spread out
neither; doesn’t depend on shape

Angular acceleration will definitely increase if:
torque is decreased and momentum of inertia is decreased
torque is decreased and momentum of inertia is increased
torque is increased and momentum of inertia is decreased
torque is increased and momentum of inertia is increased

Compare a ball rolling down a ramp (with no slipping) with a block sliding down another ramp at the same angle (with no friction). Which one will reach the bottom first?
the ball
the block
same time

Ralph heard his instructor say "Moment of inertia plays the same role in rotational motion that mass does in linear motion." This confuses him. In your own words, explain to Ralph what that means. (I don't want equations. I just want a short conceptual explanation.)