Question

a car moving at 40 km/hris to be stopped by appliying breaks in the next 4 four m if the car weighs 2000kg what average force must be applied on it

Answer 1

Hello, here’s the answer

Initial speed of the car, u = 40km/hr = 400/36m/s

Stopping distance of the car, s = 4m

According to the 2nd equation of motion,

v2 - u2 = 2as

02 - (400/36)2 = 2a x 4

400/36 x 400/36 = 8a

-15.4m/s2 = a

Now,

Mass of the car, m = 2000kg

F = ma

F = 2000 x -15.4

F = 30800 N