Question

A car moving with a velocity of 30 m/s is subjected to uniform retardation of 3 m/s² . The time taken by the car to come to rest is __​

Answer 1

Answer:

Data are given,

u = 30m/s

v= 0 m/s

a= -3m/s^2

t=?

by using the formula,

v=u+at

t= ( v-u) / a

t= ( 0- 30) / -3

t= 10s

Answer 2

Given:

Initial velocity ( u ) = 30 m/s

The car comes to rest

So, Final velocity ( v ) = 0 m/s

Uniform Retardation = 3 m/s²

We know that

Retardation is nothing but negative acceleration i.e Retardation = - Acceleration

So, Uniform acceleration ( a ) = - 3 m/s²

Let the time taken to come to rest be t seconds

From 1st equation of motion

=> v = u + at

=> 0 = 30 + ( - 3 )t

=> 0 = 30 - 3t

=> 3t = 30

=> t = 30 / 3

=> t = 10

Therefore the time taken by the moving to come to rest is 10 seconds.