Question

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

Answer 1

Explanation:

since the particle completes one revolution in 40 sec

which means in 40 sec it completes 2Πr m

distance it completes in 140 sec = ( 2Πr x 140 )÷40

= 7Π r m

Now 2Πr means 1 full revolution

4Πr means 2 full revolution

6Πr. " 3. " "

and so on..

and Πr means 1 half revolution

3Πr means 2 half revolution and so on .....

therefore it comes to point opposite to the starting point in the circle after completeing 7Πr rounds

which means it is only Πr m away from the starting point.

and hence displacement = Πr