Question

A 120 meter long train will cross 330 meter long bridge. The speed of the train is 30 km per hour. Question (a): what is the total distance crossed by the train? Question (b): How much time will the train need to cross the bridge? Question (c): If the speed of the train is increased 10 km per hour and it crosses a platform in that time determine the length of the platform.

Answer 1

a) Total distance crossed by train = (330+120) m= 450 m.
b) Time needed by train to cross the bridge = Distance /Speed = 450m / 30kmph = 450/(25/3) s = 54 s.
c) Now, As per the question,
Speed = 30+10 = 40 kmph = 100/9 m/s
Time taken = 54 s.
First, we calculate the distance covered in 54 s i.e. 600 m
Now, length of platform = (600-120)= 480 m