Question

A car is moving with velocity 40ms-¹ and come to rest in 20 sec. After applying break the acceleration of a car is.​

Answer 1

Answer:

Given

initial velocity (u) = 40 m/s

Final velocity ( V) = 0 m/s

Time taken ( T ) = 20 second

now first we find the retardation after then we find distance.

V= u + at

or, a =( V- u)/T

or a = -40/20

or a = - 2 m/s²

now V² = u² + 2as

or S = - (40)²/ 2 (-2)

or S = 400 m

hence distance coveres before come to rest is 400m

Answer 2

Answer:

2m s^-2

Explanation:

v = 0m s^-1

u = 40m s^-1

a = ?

t = 20s

a = (v-u)/t

= (40 - 0)/20

= 2m s^-2