Speed of a moving observer toward stationary source (sound frequency)

In summary, the conversation discusses the use of an equation for determining the velocity of a car based on the frequency of a stationary whistle and the speed of sound. The correct equation is given, but the individual asking for help seems to be making mistakes in their math and arriving at incorrect answers. The conversation ends with the individual receiving the correct answer and asking for help with another problem.
  • #1
rechitzy
21
0

Homework Statement



A stationary whistle emits a sound of 190 Hz. If a car hears the whistle with a frequency of 198 Hz, how fast was it moving (in m/s)? Use 340 m/s for the sound velocity

Homework Equations



f'=(1+Vo/V)f ======>>>> equation for the observer moving toward stationary source.

The Attempt at a Solution



f'=(1+Vo/V)f

198=(1+Vo/340)190

please help! what am i doing wrong?
 
Physics news on Phys.org
  • #2
What did you get for your answer?
 
  • #3
i got 353.3157
 
  • #4
Well, then you made a mistake in your math. I believe your equation is right, but you seem to be messing up when solving the algebra. Your velocity should not be that fast.
 
  • #5
ok i believe i did the 198/190 times 340 -1 is that right?
 
  • #6
No, it's not.
 
  • #7
ok i got a different answer now 14.3157 is this one right?
 
  • #8

FAQ: Speed of a moving observer toward stationary source (sound frequency)

What is the speed of a moving observer towards a stationary source of sound frequency?

The speed of a moving observer towards a stationary source of sound frequency is the relative speed between the observer and the source. It is the speed at which the observer is moving towards the source, and it affects the frequency of the sound wave that the observer perceives.

How does the speed of a moving observer affect the frequency of sound?

The speed of a moving observer affects the frequency of sound through the Doppler effect. When an observer is moving towards a stationary sound source, the perceived frequency of the sound will be higher than the actual frequency. This is because the sound waves are compressed as they reach the observer, resulting in a higher frequency.

What is the formula for calculating the perceived frequency of sound due to the Doppler effect?

The formula for calculating the perceived frequency of sound due to the Doppler effect is: f' = f(v + vo)/(v + vs), where f' is the perceived frequency, f is the actual frequency, v is the speed of sound, vo is the speed of the observer, and vs is the speed of the source. This formula applies when the observer is moving towards the source.

Does the speed of the source affect the perceived frequency of sound?

Yes, the speed of the source does affect the perceived frequency of sound. When the source is moving towards the observer, the perceived frequency will be higher than the actual frequency, just like when the observer is moving towards the source. However, when the source is moving away from the observer, the perceived frequency will be lower than the actual frequency.

What are some real-world applications of understanding the speed of a moving observer towards a stationary source of sound frequency?

Understanding the speed of a moving observer towards a stationary source of sound frequency has various real-world applications. It is important in fields such as meteorology, where the Doppler effect is used to measure the speed and direction of wind by analyzing the frequency of sound waves. It is also used in astronomy to measure the movement of stars and galaxies. In addition, the Doppler effect is utilized in medical imaging techniques like ultrasound to create images of internal organs and tissues.

Back
Top