Question

A 4.6-m-diameter merry-go-round is initially turning with a 3.9 s period. It slows down and stops in 21 s. Before slowing, what is the speed of a child on the rim?

Answer 1

S = V t = V P where S is distance traveled and P the period

2 π R = V P

V = 2 π R / P = D π / P since D = 2 * R

V = 4.6 * π / 3.9 = 3.7 m/s