Two trains are moving towards each other and cross each other. The apparent pitch

Two aeroplanes are moving towards each other and cross each other. Then the apparent pitch

Two aeroplanes are moving towards each other. One of them blows a horn the person in the other plane hears the sound. The apparent pitch will

Two trains P and Q whose front ends are 539 km apart. They start at the same time towards each other and cross each other after 200 minutes. The ratio of length of these trains is 3 ∶ 2 and their speeds are 90 km/hr and 72 km/hr. Find the difference of the length of these two trains.

Can two streamlins cross each other?

Two balls are moving towards each other on a vertical line collides with each other as shown. Find their velocities just after collision.

Two trains, each moving with a velocity of 30 ms^-1 , cross each other. One of the trains gives a whistle whose frequency is 600 Hz. If the speed of sound is 330 ms^-1 , the apparent frequency for passengers sitting in the other train before crossing would be

When an observer moves towards a stationary source, then the apparent pitch will