Question

1. Two trains 115 m and 135 m long are running along parallel tracks at the speeds of
35 km/h and 45 km/h respectively. How long will they take to pass by each other if they run
(i) in opposite directions (ii) in the same direction?
2. Ravi and John​

Answer 1

In Same direction

total length of train=115+135=250m

Relative speed=45-35=10km/h

In meter per second=10x5/18=25/9

Time taken = 250/25/9=250x9/25=10x9=90 sec

90 sec in min =1min30sec

In opposite directions

Length of train=250m

Relative speed=45+35=80 km/h

In m/s=80x5/18=200/9 m/s

Time taken= 250/200/9=250x9/200= 7.5sec