Question

A train 80 m long travelling at 30 m/s overtakes another train 100 m long
travelling at 20 m/s. Calculate the time taken by the first train to overtake
the second train.​

Answer 1

Explanation:

Relative velocity of overtaking =40−30=10m/s

Total relative distance covered with this relative velocity during overtaking

=100+200=300m

So, time taken =

10

300

=30s

Answer 2

Answer:

18 seconds

Explanation:

s=80+100=180m

relative velocity=30-20=10m/s

s/t=relative velocity

s/relative velocity=t

180/10=18sec