Question

If you were enclosed in a small windowless room which was mounted on a (ver smooth) merry-go-round, how could you know if the merry-go-round was rotating?

Answer 1

put some object on the floor...it'll try to move radially outward..
hang a pendulum bob from the ceiling...it wont hang vertically downward..

Answer 2

does it make sense?

Answer 3

yea yea~ the book's answer mentioned about the pendulum but doesn't explain about it~ now I get it~ thanks :))

Answer 4

ok...:)