A violin player riding on a slow train plays a 440 Hz note. Another violin player standing near the track plays the same note. When the two are close by and the train approaches the person on the ground, he hears 4'0 beats per second. The speed of sound in air` = 340 ms^-1` (a) Calculate the speed of the train. (b) What beat frequency is heard by the player in the train ?

Answer

A, B, D

Explanation

let the velocity of the sources `=v_s`
a. the beat herd by the standing man =4
So frequency =440+4
`=444 Hz or 436 Hz`
`rarr 440=((340+0+0+)/(340-v_s))xx400`
o solving we get
`V-s=3.06 m/s=11 km/hr`
b. The sitting man wil listenless number of beats than 4.