Question

a car weight 1000 kg travelling at 30 meter second stop at distance of 50m distance learning uniformly ? what is the force exerted ? on it by the brakes ? what is the work done by the brakes

Answer 1

Mass= 1000
initial velocity= u= 30
final velocity= v= 0
distance= s= 50
as we know 
v²= u²+ 2as
0²= 30² + 2 a 50
-900= 100a
a= -9

And F= ma
F= 1000 x -9
F= -9000N

W= Fs
W= -9000 x 50
= -450 KJ