The whistle of an engine moving at `30km//h` is heard by a motorist driving at `15km//h` and he estimated the pitch to be 500. What would be the actual pitch if two are approaching each other ? Velocity of sound is 1220km//h .

An engine moving with a velocity of 36 km // hour blows a whistle which is heard by a motorist driving with 18km//hr to be 500 c.p.s. Calculate the actual frequency, when (a) Two are moving in opposite directions and approaching each other. (b) Two are moving in opposite directions and receding away. (c) Two are moving in the same direction , but motorist is behind the engine. (d) Two are moving in same direction but motorist is in front of engine. Velocity of sound =330 metre // sec

Two cars P and Q are approaching each other with velocities of 36 km/h and 72 km/h respectively. The frequency of a note emitted by car P as heard by the person sitting in car Q is 850 Hz. What will be the frequency of note heard by person sitting in car P ? Velocity of sound = 340 m/s.

Two trains A and B are approaching each other with 108 km h^(-1) and 126 km h^(-1) , respectively . If the train A sounds a whistle of frequency 500 Hz , find the frequency of the whistle as heard by a passenger in the train B . (a) before the trains cross each other and (b) after the trains cross each other . (Take velocity of sound as 330 m s^(-1) )

A ship is moving at a speed of 56 km//h . One second later , it is moving at 58 km//h . What is its acceleration?

The sirens of two fire engines have a frequency of 600 Hz each . A man hears the sirens from two engines, one approaching him with a velocity of 36km//h and the other going away from him at a speed of 54km//h . What is the difference in frequencies of sound heard ? Take velocity of sound in air =340m//s .

Two aeroplanes are approaching eachother and their velocities are 100 and 240 km // h . The frequency of a note emitted by the first as heard by the passengers in the other is 100. Calculate the true frequency of the note as head by its own passengers. Take the velocity of sound as 1200km.//hr.

A train moving with a velocity of 18 km/hr blows a whistle which is heard by a motor cyclist driving with speed of 6 km/h with the frequency received as 200 cps. The actual frequency when train and motor cyclist are moving in opposite directions and approaching towards each other will be (Speed of sound is 340 m/s, cps is cycle per second)

Two buses X and Y are approaching each other and their velocities are 120 km/hr and 140 km/hr, respectively. The frequency of horn emitted by X as heard by the passengers in Y is 1100 Hz. What will be the frequency of the horn heard by the passenger in X. Velocity of sound = 340 m/s.

A car is moving with a velocity of 60km//h due east and a train is moving with a velocity of 80km//h due south . For a passenger sitting inside the train , what is the velocity of car appearing to him ?