A500 hz whistle is moved toward a listener at a speed of 10 m/s. at the same time, the listener moves at a speed of 20 m/s in a direction away fromm the whistle. what is the apparent frequency heard by the listener? (the speed of sound is 340 m/s)
a) 473 hz
b) 376 hz
c) 485 hz
d) 533 hz
e) 547hz

Frequency will be 485 Hz

So option (c) will be the correct option

Explanation:

We have given frequency f = 500 Hz

Velocity of observer

Velocity of source

When both observer and source are moving then frequency is given by

, here v is the velocity of sound

So

So option (c) will be the correct option

pe = weightxheight = 2000x1000=2,000,000joules