An athlete completes one round of a circular track of diameter 70 m in

1.	An athlete completes one round of a circular track of diameter 70 m in the 30s. Find (i) the distance travelled by the athlete (ii) the magnitude of displacement of the athlete at the end of 30 s.
Answer» Answer :- GIVEN :- Diameter = 70 m Time taken to COMPLETE one round = 30 s To Find :- Distance travelled Displacement Solution :- Calculating Distance travelled :- Here, the athlete complete one round. So, distance travelled will be equal to the circumference of the circle. Diameter = 70 m → RADIUS = 70 / 2 = 35 m Distance = 2πr = 2 × 22 / 7 × 35 = 2 × 22 × 5 = 22 × 10 = 220 Distance travelled = 220 m Calculating Displacement :- Here, the athlete completes one round in 30 seconds i.e. it comes to initial position after 30 seconds. So, displacement of athlete is zero. Displacement = 0

An athlete completes one round of a circular track of diameter 70 m in the 30s. Find (i) the distance travelled by the athlete (ii) the magnitude of displacement of the athlete at the end of 30 s.

Answer»

Calculating Distance travelled :-

Here, the athlete complete one round. So, distance travelled will be equal to the circumference of the circle.

→ RADIUS = 70 / 2 = 35 m

Distance = 2πr

= 2 × 22 / 7 × 35

= 2 × 22 × 5

= 22 × 10

= 220

Calculating Displacement :-

Here, the athlete completes one round in 30 seconds i.e. it comes to initial position after 30 seconds. So, displacement of athlete is zero.