Question

A car traveling at 45 km/h starts to brake, and comes to a stop over a distance of 18 m. Calculate the acceleration

of the braking car.

Answer 1

Acceleration,
`a=8.68\ m/s^2`

Step-by-step explanation:

Given that,

Initial speed of a car, u = 45 km/h = 12.5 m/s

Final speed, v = 0 (as they comes to rest)

Distance, d = 18 m

We need to find the acceleration of the breaking car. Using third equation of motion as follows :

`v^2-u^2=2ad\\\\\text{Where a is acceleration of the car}\\\\a=(v^2-u^2)/(d)\\\\a=((12.5)^2)/(18)\\\\a=8.68\ m/s^2`

So, the acceleration of the braking car is
`8.68\ m/s^2`.