Question

A typical running track is an oval with 74-mm-diameter half circles at each end. A runner going once around the track covers a distance of 400 mm . Suppose a runner, moving at a constant speed, goes once around the track in 1 minmin 40 s.What is her centripetal acceleration during the turn at each end of the track?

Answer 1

The centripetal acceleration a is 4.32 $\times$ 10^-4 m/s^2.

Explanation:

The speed is constant and computing the speed from the distance and time for one full lap.

Given, distance = 400 mm = 0.4 m,       Time = 100 s.

Computing the v = 0.4 m / 100 s

                         v = 4 $\times$ 10^-3 m/s.

radius of the circular end r = 37 mm = 0.037 m.

            centripetal acceleration a = v^2 / r

                                                        = (4 $\times$ 10^-3)^2 / 0.037

                                                    a = 4.32 $\times$ 10^-4 m/s^2.