Question

20] A car is speeding along a level road at 25 m/s. The brakes bring the 500 kg car to a speed of 3
m/s over a distance of 5 m. Determine the force by brakes and work done on the car by brakes​

Answer 1

Answer:

Explanation:

u = 25 m/s

v = 3 m/s

S = 5m

Apply the following values to the 3rd equation of motion

v^2 - u^2 = 2aS

3^2 - 25^2 = 2 x - a x 5

-616 = -10a

a = 61.6 m/s^2

Now F = ma

=> F = 500 x 61.6

=> F = -  30800N