Question

A car is traveling at 20 meters/second and is brought to rest by applying brakes over a period of 4 seconds what is its average acceleration over this time interval?

Answer 1

Avg. acceleration = -5 m/s^2.

Answer 2

Acceleration of the car is
`-5\ m/s^2`

Step-by-step explanation:

It is given that,

Initial speed of the car, u = 20 m/s

Finally, it brought to rest, v = 0

Time taken, t = 4 s

We need to find the average acceleration over this time interval. The acceleration of an object is given by following formula as :

`a=(v-u)/(t)`

`a=(-(20\ m/s))/(4\ s)`

`a=-5\ m/s^2`

So, the car is decelerating at
`5\ m/s^2`. Hence, this is the required solution.