Question

A moving train is brought to rest within 20 seconds by applying brakers.Find the initial velocity,if the retardation due to brakes is 2m/s^2.

Answer 1

Answer:

Given:

Final velocity v = 0

Time taken t = 20 s

Acceleration a = -2 m/s2

From the equation v = u + at, we have

u = v - at

→ u = 0 - (-2) × 20

→ u = 40 m/s2

Answer 2

Answer:

A moving train is brought to rest within 20 seconds by applying brakers.Find the initial velocity,if the retardation due to brakes is 2m/s^2.

Explanation:

Given,

=Final velocity (as train comes to rest) = 0

= t = 20 s.

= a = 2 m/s^2

v=u+at

0 = u + 20*(-2)

u = 40 m/s.