Question

An athlete takes 40 second to move on a circular path of diameter 200 m. What will be his
displacement after 2 minutes 20 seconds.
(A) 100 m (B) 200 m
(C) zero (D) 400 m

Answer 1

Solution :-

As per the given data ,

• Time taken to complete 1 round = 40 s
• Diameter = 200 m

We need to find the displacement of the athlete after 2  min and 20 sec

i.e. 140 s

The athlete completes 1 round in 40 s

No of rounds completed in 140 s = 140 / 40 = 3.5 rounds

The athlete covers 3.5 rounds in 140 s

i.e. 3 complete rounds - [displacement = 0 ] as the initial and final position of the athlete is the same

one half round - [ displacement = d= 200 m ] here d is the diameter of the circular path

Note : -

Displacement is the shortest path traveled by the body between it's initial and final position

It is a vector quantity .

The displacement of the athlete after 2 m 20s is 200 m