Two trains are each 50 m long moving parallel towards each other at speeds `10 ms^(-1)` and `15 ms^(-1)` respectively, at what time will they pass each other ?

Two trains are each 50m long moving parallel towards each other at speeds 10 m/s and 15 m/s respectively, at what time will they pass each other?

Two trains each of length 100 m moving parallel towards each other at speed 72km/h and 36km/h respectively. In how much time will they cross each other?

Two trains each of length 100 m moving parallel towards each other at speed 72km/h and 36km/h respectively. In how much time will they cross each other?

The velocity of image object and mirror both are moving towards each other with velocities 4ms^(-1) and 5ms^(-1) respectively, is

Two trains each 200 m long move towards each other on parallel lines with velocities 20 kmph and 30 kmph respectively. What is the time that elapses when they first meet until they have cleared each other?