Question

A body complete one round of a circle of radius R in 20 seconds the displacement of the body after 45 seconds is

Answer 1

Answer:

(πR)/2

Explanation:

it will complete two rounds in 40 sec.

now we have to calculate the displacement in 5 sec.

it covers 2πR in 20 sec

so it will cover (2πR)/20 in 1sec

the displacement in 5 sec=((2πR)*5)/20

=(πR)/2

Answer 2

Answer:  2^(1÷2)R

Explanation:

Displacement is the shortest distance between the initial and final positions of the body

By the first 20 second , it returns to the initial position and hence the net displacement is zero..by the next 20 second , it again reaches the same point and the displacement is zero..and by the remaining 5 seconds..it covers 1÷4rth of the circle..

Therefore..the displacement is the chord length which is root 2 times the radius..