An athlete completes one round of a ciruclar track of radius R in 40 seconds. What will be his diplacement at the end of 2 minute 20 second?

Explanation

Diameter `= 200 m therefore r = 100 m`
Time for one round of the track = 40 s `therefore` In 2 min 20 sec = 140 s, the athlete will complete `(140)/(40) = 3.5` rounds of the track.
Distance covered in one round
= the circumference `=2pi r `
`therefore` distance covered in `3.5` rounds
`= 2 xx (22)/(7) xx 100 xx 3.5= 2200 m`
Displacement after `3.5` rounds, the athlete will be in the diametrically opposite position.
`therefore ` displacement = diameter of the track = 200 m
The distance covered `= 2200 m,` displacement `= 200 m.`