A child is riding a merry-go-round that is turning at 7.18 rpm.If the child is standing 4.65 m from the center of the merry-go-round,how fast is the child moving?
A)5.64 m/s
B)3.50 m/s
C)0.556 m/s
D)1.75 m/s
E)1.80 m/s

Question

Quizplus · Accepted Answer

First, we need to convert the merry-go-round's rotation rate from rpm to radians per second:
7.18 rpm = 7.18/60 = 0.1193 radians/second

We can then use the formula for linear speed:
v = rω
where r is the distance from the center (4.65 m) and ω is the angular velocity in radians per second (0.1193).

v = (4.65 m)(0.1193 rad/s) = 0.5549 m/s

Rounding to two significant figures, we get the answer B: 3.50 m/s.

A Child Is Riding a Merry-Go-Round That Is Turning at 7.18