# Warm-Up Exercise for lecture 13

## Due 8:00 am, Tues, Oct 14

Physics 105, Fall 2008

Which has greater linear speed, a horse near the outside rail of a merry-go-round or a horse near the inside rail?
outside horse
inside horse
both the same

Which has greater angular speed, a horse near the outside rail of a merry-go-round or a horse near the inside rail?
outside horse
inside horse
both the same

A ladybug sits on the outer edge of a merry-go-round that is turning around counter-clockwise without speeding up or slowing down. In what direction is the friction force sticking the ladybug to the merry-go-round?
clockwise
counter-clockwise
inward
outward

Ralph is confused about centripetal and centrifugal forces. When he is in a car which is turning to the left, he feels a force pushing him to the right. But the textbook says that the actual force is pushing him to the left. Can you explain this to him? What is he feeling during the turn? (Please: no more of the "Tell Ralph to stop asking questions" or "Tell Ralph to ask Dr Colton" answers. They were funny at first, but now that I'm getting ~50 of them for each warmup, it has kind of gotten old. Just give it your best shot at a real explanation, or leave it blank. Or write some *other* funny comment. ;-) Thanks.)