Question

the particle moves on a circular path of radius r and it complete one revolution in 40 second calculate distance and displacement in 2 minutes one 20 second​

Answer 1

Radius of circular path = R
Time =2 minutes 20 seconds=140 seconds
Distance covered in 1 second = 2πR
Time for 1 revolution =40 seconds
Revolution completed in 140 seconds = 140/40=3.5
Distance covered in 3.5 revolution = 3.5*2πR = 7πR metres
Displacement in 3.5 revolution = 2R metres (shortest distance between initial and final distance).
Ratio of displacement to distance:-
=2R/7πR
= 2/7π