A trumpet player on a moving railroad flatcar moves toward a second trumpet player standing alongside the track both play a 490 Hz note. The sound waves heard by a stationary observer between the two players have a beat frequency of 2.0 beats/s. What is the flatcar's speed? Take the speed of sound to be 343 m/s.

The value is

Explanation:

From the question we are told that

The frequency of the second player is

The beat frequency is

The speed of sound is

Generally the frequency of the note played by the first player is mathematically represented as

=>

=>

From the relation of Doppler Shift we have that

Here

So

=>

truck y has a greater velocity than truck x.