Question

ANSWER WITH EXPLANATION TO GET THE POINTS YOU DESERVE:-))))
An athlete completes one round of a circular track of radius R in 40 seconds. The displacement at the endof 2 minutes 20 seconds will be
A) Zero B) 2 R C) πR D) 7 R

Answer 1

Distance Covered by Athelete = 2πr

Time Taken to complete = 40s

So, as 1 round takes 40 s

So, in 1s, he will complete 1/40 rounds.

Therefore, in 2min 20s = 140 s, He will cover

1/40 * 140 = 7/2 rounds = 3.5 rounds

This means, the athlete completes 3 complete rounds and half a round.

So, he will be standing at half of the circumference.

So, the Displacement becomes the Diameter = r + r = 2r