Question

An athlete completes one round of a circular trake of diemeter 200m in 40ses.what will be the distance,displacement,speed and velocity after 2min 20sec​

Answer 1

Answer:

Explanation:

Diameter = 200 m, therefore, radius = 200m/2 = 100 m

 

Time of one rotation = 40s

Time after 2m20s = (2 x 60s + 20s) = 140s

We know that, velocity along a circular path

= (Circumference/time)

⇒v =(2πr/40s)

⇒v= (2×3.14×100m/40s)

⇒v= (628m/40s)

⇒v=15.7m/s

(a) Distance after 140s

We know that, distance=velocity ×time

⇒ distance= (15.7m/s ×140 s) = 2198 m

(b) Displacement after 2 m 20 s i.e. in 140 s

Since, rotating in 40 s=1

Therefore, rotation in

1s=140

∴ rotation in 140s=(1/40)×140=3.5

Therefore, in 3.5 rotations athlete will be just at the opposite side of the circular track, i.e. at a distance equal to the diameter of the circular track which is equal to 200 m.

Therefore, Distance covered in 2 m 20 s = 2198 m

And, displacement after 2 m 20 s = 200m