Question

A child on a spinning ride at a playground has a centripetal acceleration of 0.80 m/s2. The child completes a full circle every 4.2 s.

How far from the center of the ride is the child?

0.068 m
0.085 m
0.27 m
0.36 m

Answer 1

Use a = 4π^2 r / T^2. Solve for r: r = a T^2 / (4π^2).

Plug in a = 0.80 m/s^2 and T = 4.2 s:
r = (0.80)(4.2^2) / (4π^2) = (0.80)(17.64) / 39.478 = 14.112 / 39.478 ≈ 0.357 m ≈ 0.36 m.

Answer: 0.36 m.