A 5.0-m-diameter merry-go-round is turning with a 3.7 s period. Part A What is the speed of a child on the rim

Speed of a child on the rim is 4.25 m/s.

Explanation:

Given;

diameter of the merry-go-round, d = 5.0 m

period of the motion, t = 3.7 s

one complete rotation of the merry-go-round = πd

one complete rotation of the merry-go-round = π(5) = 15.71 m

Speed is given as distance / time

speed of a child on the rim = 15.71 / 3.7

speed of a child on the rim = 4.25 m/s

Therefore, speed of a child on the rim is 4.25 m/s.

one "light year" is the distance that light travels, through vacuum, in one julian year.   that's 365.25 days, of 24 hours each.