Question

A train is moving at a velocity of 25 ms-1. It is brought to rest by applying the brakes which produces a uniform retardation of 0.5 ms-2. 
Calculate :
(i) the velocity of the train after 10 s
(ii) If the mass of the train is 20000 kg then calculate the force required to stop the train

Answer 1

(i) ★ v = u – at

= 25 - 0.5 × 10

= 20 m/s

(ii) Mass = 20000 kg.

We know that,

★ Force = mass x acceleration

= 20000 × 0.5

= 10000 N

Answer 2

Answer:

Force : The push or pull exerted on a body .

Velocity: Rate of change of displacement

Acceleration: Rate of change of velocity

=< Acceleration is also called as retardation or deceleration.

Refer pic for answer