Question

A circular track has several concentric rings where people can run at their leisure. Phil runs on the outermost track with radius rP while Annie runs on an inner track with radius rA = 0.90 rP. The runners start side by side, along a radial line, and run at the same speed in a counterclockwise direction.How many revolutions has Annie made when Annie's and Phil's velocity vectors point in opposite directions for the first time?

Answer 1

Assuming that the runners start at the same point and run at the same speed, Annie will have made one revolution when their velocity vectors point in opposite directions for the first time.