Question

an athlete completes one round of a circular track of diameter 200 m in 40 s.what will be the displacement at the end of 2 minutes 20 s​

Answer 1

Solution :

• Diameter of the circular track = 200 m

• Time taken in order to complete 1 round = 40 s

We need to find the displacement at the end of 2 m 20 s

Now , displacement is the shortest distance traveled by the object between it's initial and final position

Displacement is a vector quantity

• Time taken = 2 m 20 s = 120 + 20 = 140 s

If the athlete completes 1 round in 40 s number of rounds covered in 140 s

= 140 / 40

= 3.5

Hence , the total number of rounds completed by the object in 2m 20 s i.e. 140s = 3.5 rounds

3.5 rounds means the athlete has  completed 3 full rounds ( displacement will be zero as the initial and final position of the object is the same )

and one half round ( displacement = d )

here ,

d represents the diameter of the circular track

Hence the displacement of the athlete at the end of 2m 20 s is 200 m

Answer 2

Solution :

Diameter of the circular track = 200 m

Time taken in order to complete 1 round = 40 s

We need to find the displacement at the end of 2 m 20 s

Now , displacement is the shortest distance traveled by the object between it's initial and final position

Displacement is a vector quantity

Time taken = 2 m 20 s = 120 + 20 = 140 s

If the athlete completes 1 round in 40 s number of rounds covered in 140 s

= 140 / 40

= 3.5

Hence , the total number of rounds completed by the object in 2m 20 s i.e. 140s = 3.5 rounds

3.5 rounds means the athlete has  completed 3 full rounds ( displacement will be zero as the initial and final position of the object is the same )

and one half round ( displacement = d )

here ,

d represents the diameter of the circular track

Hence the displacement of the athlete at the end of 2m 20 s is 200 m