Question

A net force of –8750N is used to stop of 1250.kg car travelling 25m/s. What braking distance is needed to bring the car to a halt?

Answer 1

d = 44.64 m

Step-by-step explanation:

Given that,

Net force acting on the car, F = -8750 N

The mass of the car, m = 1250 kg

Initial speed of the car, u = 25 m/s

Final speed, v = 0 (it stops)

The formula for the net force is :

F = ma

a is acceleration of the car

`a=(F)/(m)\\\\a=(-8750)/(1250)\\\\a=-7\ m/s^2`

Let d be the breaking distance. It can be calculated using third equation of motion as :

`v^2-u^2=2ad\\\\d=(v^2-u^2)/(2a)\\\\d=(0^2-(25)^2)/(2* (-7))\\\\d=44.64\ m`

So, the required distance covered by the car is 44.64 m.