The driver of a train travelling at 40 ms^-1 applies the brakes as a train enters a station.

Question

The driver of a train traveling at 40 ms^-1 applies the brakes as a train enters a station. The train slows down at a rate of 2 ms^-2. The platform is 400 m long. Will the train stop in time?

Answer 1

Given:

Initial Speed = u = 40 ms^-1 

Acceleration = a = - 2 ms^-2 (Retardation, hence negative) 

Final Speed = v 

Now, s = Distance train travels before stopping 

Now, we know from the equations of motion that,

v² = u² +2as

0 = 40² +2 \(\times\) (-2) \(\times\) s

4s = 1600

s = 400 m 

So, the train covers 400 m before stopping. 

Also, the length of platform = 400 m. 

So, the train stops in time.