Running in opposite directions around a circular track

HOME

Math Central

Quandaries & Queries

Question from Alessandra:

2. Alan and Brian are two runners. Alan runs at 6.6 m/s and Brian runs at 8.4 m/s. They start from
the same place on a circular 400 m track and run in opposite directions round and round the
track.
(a) How far has Brian run when they pass each other for the first time?
(b) After they pass each other for the second time, how much further does Brian need to run
in order to complete two laps (800 m)?

Hi Alessandra,

Alan and Brian are running in opposite directions around the track. When they start they are 400 meters apart. Alan is running at 6.6 m/s and Brian at 8.4 m/s. At what rate is the distance between them decreasing? At this rate how long will it take for the distance between them to decrease to zero?

Penny

Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences.