Question

17. Two trains starting at the same time, having lengths 200 m each are moving in same direction. If the
speed of each train is 30 km/h and 35 km/h respectively, find when they will cross each other.​

Answer 1

Let the -

• time taken by both the trains to cross each other be x hrs.

Length of two trains is 200 m.

→ 200/1000 = 0.2 km

Speed by one train is 30 km/hr.

So,

$\boxed{\sf{Distance\:=\:Speed\:\times\:time}}$

→ 30 × x

→ 30x km ....(1)

Similarly, the speed of second train is 35 km/hr.

$\boxed{\sf{Distance\:=\:Speed\:\times\:time}}$

→ 35 × x

→ 35x km ....(2)

According to question,

Both trains are moving in same direction. We have to find the time taken by both the trains to cross each other.

→ Speed of second train - Speed of one train = Length of both trains

Substitute the known values above

→ 35x - 30x = 0.2

→ 5x = 0.2

→ x = 0.2/5

→ x = 0.04 hrs.

•°• Time taken by both the trains to cross each.h other is 0.04 hrs.