wave_mechanics critical_thinking Question 16
Question: A police car moving at 22 m/s, chases a motorcyclist. The police man sounds his horn at 176 Hz, while both of them move towards a stationary siren of frequency 165 Hz. Calculate the speed of the motorcycle, if it is given that he does not observes any beats
[IIT-JEE (Screening) 2003]
Options:
A) 33 m/s
B) 22 m/s
C) Zero
D) 11 m/s
Show Answer
Answer:
Correct Answer: B
Solution:
$ n _{1} $ = Frequency of the police car horn observer heard by motorcyclist $ n _{2} $ = Frequency of the siren heard by motorcyclist.
v2 = Speed of motor cyclist $ n _{1} $ = $ \frac{330-v}{330-22}\times 176;n _{2}=\frac{330+v}{330}\times 165 $
$ \because $
$ n _{1}-n _{2}=0\Rightarrow v=22 $
$ m/s $ .
BETA
