Question

Find the initial velocity of a car ,which is stopped in 20 seconds by applying brakes the retardation due to brakes is 4.5 metre per second square?​

Answer 1

Answer:

Initial velocity, u=?

Final velocity, v=0m/s (car is stopped)

Acceleration, a=−2.5m/s

2

(negative because it is retardation)

Time, t=10s

Use the relation of the first equation of motion:

v=u+at

0=u+(−2.5)×10

u=25m/s