Question

A car is regarded by applying the brakes at rate of 2m/s square. It is finally stopped in 10 s. Find its initial velocity.

Answer 1

Answer:

Initial velocity = 20 m/s

Explanation:

v = 0 m/s (car stops)

a = - 2m/$s^{2}$

t = 10 s

u = ?

v = u + at

u = v - at

  = 0 + 2 x 10

  = 20 m/s

Answer 2

Answer:

u=20 m/s

Explanation:

from first equation of motion, v= u+ at

0= u + (-2)(10)            ["-" for acceleration as it retards motion]

u - 20 m/s