Question

1) The brakes applied to a car produce an acceleration of 6 ms in the opposite direction to the
motion. If the car takes 2s to stop after the application of brakes,
a) calculate the initial velocity of the car and
b) calculate the distance it travels during this time.​

Answer 1

Answer:

Explanation:

Here acceleration , a = - 6m/s²

time , t = 2 sec

velocity after applying brakes = 0 m/s

i) to find = initial velocity of the car , u

 by the first equation of motion ,

v = u + at

∴ 0 = u + (-6) 2

∴ 0 = u -12

∴ u = 12 m/s

ii) to find the distance it travels during this time , s

by the second equation of motion,

s = ut + 1/2 at²

s = 12 x 2 + 1/2 ( -6) (2)²

∴ s = 24 + 1/2 (-24)

∴ s = 24 - 12 = 12m