Question

a train is moving with a velocity of 90 km/h.It is brought to stop by applying the brakes which produce a retardation of 0.5 m/s2. find the velocity after 10 s and the time taken by the train to come to rest

Answer 1

Equation to be applied  " v = u - a×t ", v is final velocity, u is initial velocity, a is retardation and t is time.

 

Velocity at the time of applying break = 90 km/h  = 90 km/h × (5/18) = 25 m/s 

 

(1) Velocity after 10 s :-   v = 25-(1/2)×10 = 20 m/s

 

(2) Time to come to rest :-  0 = 25-(1/2)×t  , solving for t ,  we get  t = 50 s