Question

speed of train is increasing linearly with time.The train passes a hut with speed 2m/sec.and acquires a speed of 12m/sec.after 10 sec. What is the speed of the train in m/sec.,5sec.after passing the hut?

Answer 1

initial speed of train, u = 2m/s

final speed of train, v = 10m/s

time taken to change the speed of train from 2m/s to 10m/s , t = 10s

using formula,

v = u + at

or, 12 = 2 + a × 10

or, a = 1m/s²

now, we have to find speed of train after 5sec .

so,again using formula, v = u + at

or, v = 2m/s + 1m/s² × 5s = 7m/s

hence, speed of train is 7m/s 5 sec after passing the hut.