Question

a train 100 metre long covers a pole in 10 seconds ,then find the time it will take to covers a bridge 1 km long

Answer 1

While, crossing a pole which is a vertical object the train covers a distance, equal to its own length.
Therefore, speed of the train
= 100m/10s
=10m/s

Distance covered by the train while crossing the bridge
= length of the bridge + length of the train
= (1000 +100)m
= 1100m

Hence time taken
=1100m /10m/s
= 110s
= 1 minute 50 seconds