Sound WavesHardBloom L3
Question
A source is moving with constant speed vs = 20 m/sec towards a stationary observer due east of source. Wind is blowing at the speed of 20 m/sec due to 60° north of east. The source is generating of frequency 500 Hz. Then frequency registered by observer is: [Speed of sound in still air = 330 m/sec.]
Options
A.500 Hz
B.532 Hz
C.531 Hz
D.530 Hz
Solution
Sol. Along line joining source and observer
vs/w = 20 – 20 cos 60°
= 10 m/s
vo/w = – 20 cos 60° = – 10 m/s
f = $\left( \frac{330 + |v_{o/w}|}{330 - |v_{s/w}|} \right)f_{0}$ = $\left( \frac{330 + 10}{330 - 10} \right) \times 500$
= 531 Hz
Create a free account to view solution
View Solution FreeMore Sound Waves Questions
A sound waves is travelling towards right and its S-t graph is as shown for x = 0.What will be density vs x graph at t =...When two tuning forks (fork 1and fork 2)are sounded simultaneously, 4beats per second are heard. Now some type is attach...A sound absorber attenuates the sound level by 20 dB. The intensity decreases by a factor of : -...In a sinusoidal wave the time required for particular point to move from maximum displacement is 0.17 sec then the frequ...A light pointer is fixed to one prong of a tunning fork and touches a vertical plane. The fork is set into oscillations ...