Question

Find the initial velocity of a car which is stopped in 10seconds by applying brakes. The retardation due to brakes is 2.5m/s square.

Answer 1

u = ?
v = 0
a = -2.5 m/s^2
t = 10 s

v = u + at
0 = u - 2.5×10
u = 25 m/s

Initial velocity was 25 m/s