Question

An athlete complete one round of a circular track of diameter 200m what will be the distance and displacement of the athlete of 2 minutes and 20 second ​

Answer 1

Given :-

Diameter of circular track = 200 m

Radius, r = 200/2 = 100 m

Time taken by athlete to complete one round = 40 seconds.

To Find :-

Distance covered = ??

Displacement = ??

Formula to be used :-

Speed = Distance/Time

Circumference of circle = 2πr

Solution :-

2 min 20 seconds = 140 seconds

Number of rounds = 140/4 = 35

⇒ Distance covered = 35 × circumference

⇒ Distance covered = 35 × 2 × 22/7 × 100

⇒ Distance covered = 5 × 2 × 22 × 100

⇒ Distance covered = 22000 m

Hence, the distance covered at the end of 2 min 20 seconds is 22000 m or 22 km.

And displacement is 200 m as it return to initial position again.

Answer 2

Answer :-

• Time taken = 2m 20 seconds

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀= 140 seconds

• Radius (r) = 100m

In 40 sec, the athlete complete one round

So , In 140 seconds = $\dfrac{140}{40}$

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀= $\boxed {3.5round}$

❍Distance covered in 140 seconds

⠀⠀⠀⠀⠀⠀= $2\pi \: r \: \times 3.5$

⠀⠀⠀⠀⠀⠀= ${2\:\:×\:\: \dfrac{22}{7}\:\:×\:\:100\:\:×\:\:3.5}$

⠀⠀⠀⠀⠀⠀=$\boxed {2200m}$

At the end of his motion the athlete will be in the diametrically position.

${\boxed{\large{\bold{Displacement\:=\: Diameter\:=200m}}}}$