How Does Motion Affect Sound Frequency and Wavelength Calculation?

In summary: The distance will be the wavelength. In summary, ultrasound with a frequency of 4.079 MHz can be used to produce images of the human body. To find the wavelength in the body, use the formula v = f*λ and solve for λ. For the second question, use the formula v = f*λ and solve for f, with v as the speed of sound (340 m/s), and f as the frequency of the siren (587 Hz).
  • #1
Ronaldo21
30
0
Fundamental frequency!

1. Ultrasound with a frequency of 4.079 MHz can be used to produce images of the human
body.If the speed of sound in the body is the same (1.97 km/s) as in salt water, what is the
wavelength in the body?
Answer in units of m.

and

2. On a day when the wind is blowing 49.5 km/h from east to west, a fire engine
moves toward you from the west at 112 km/h and you are heading toward the fire engine at
94.6 km/h. If the fire engine has a 587 Hz siren and the speed of sound is 340 m/s, what frequency do you hear?
Answer in units of Hz.
i converted them to m/s. (340-12-30.2777)*1170/(340-12-30.27777) but i think i did it wrong. idk. grr
and i DO NOT know how to do number 1
please help!
 
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  • #2


The relationship between frequency and wavelength for any wave is
v = f*λ
That should take care of the first question.

What is your formula for the Dopplar effect in #2? The pattern of those numbers doesn't look quite right.
 
  • #3


for number 1, we're trying to find distance arent we? not velocity.
and for 2, well i converted km/h to m/s.
 
  • #4


for number 1, we're trying to find distance arent we? not velocity.
Yes, so solve the formula for λ.
 

What is fundamental frequency?

The fundamental frequency, also known as the first harmonic, is the lowest frequency at which a system can vibrate. In other words, it is the natural frequency of an object or system.

How is fundamental frequency measured?

Fundamental frequency is typically measured in Hertz (Hz), which represents the number of cycles per second. It can be measured using various methods such as sound analysis, vibrations, or electromagnetic waves.

What factors affect the fundamental frequency of a system?

The fundamental frequency of a system is affected by several factors, including the mass, stiffness, and length of the system. In general, a heavier, stiffer, or longer system will have a lower fundamental frequency than a lighter, more flexible, or shorter system.

What is the relationship between fundamental frequency and harmonics?

The fundamental frequency is the first harmonic of a system, and harmonics are integer multiples of the fundamental frequency. For example, if the fundamental frequency of a system is 100 Hz, the second harmonic will be 200 Hz, the third harmonic will be 300 Hz, and so on.

What are the applications of fundamental frequency?

Fundamental frequency has various applications in different fields. In physics, it is used to study the properties of materials and systems. In music, it determines the pitch of a sound and plays a crucial role in creating melodies and harmonies. In engineering, it is used to design structures and machines with desired frequencies and to identify potential problems or failures in systems.

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