# What is the beat frequence in Hz of ultrasound

• confused1
In summary, when ultrasound is reflected from an oncoming bloodstream moving at 30 cm/s and mixed with an original frequency of 2.5 MHz, beats are produced. To find the beat frequency in Hz, the "doppler effect" equation can be used to calculate the frequency of the reflected wave. This frequency can then be used in the beat equation along with the original frequency to determine the beat frequency in Hz. It is important to pay attention to units when using these equations.
confused1
Ultrasound reflected from an oncoming bloodstream that is moving at a 30 cm/s is mixed with the original frequency of 2.5 MHz to produce beats. What is the beat frequency in Hz? (Velocity of sound in blood = 1540 m/s.)

confused1 said:
Ultrasound reflected from an oncoming bloodstream that is moving at a 30 cm/s is mixed with the original frequency of 2.5 MHz to produce beats. What is the beat frequency in Hz? (Velocity of sound in blood = 1540 m/s.)

Find the frequency of the reflected wave using the "doppler effect" equation. Remember that the bloodstream is moving towards the observer.

Then use the beat equation with the two frequencies (2.5MHz and what you get above using doppler).

The beat frequency in Hz can be calculated using the formula:
beat frequency (Hz) = | velocity of sound (m/s) | / wavelength (m)

First, we need to convert the velocity of the bloodstream from cm/s to m/s:
30 cm/s = 0.3 m/s

Next, we can calculate the wavelength using the formula:
wavelength (m) = velocity of sound (m/s) / frequency (Hz)

Since we know the velocity of sound in blood is 1540 m/s and the frequency is 2.5 MHz, we can solve for the wavelength:
wavelength (m) = 1540 m/s / 2.5 MHz
= 0.000616 m

Now, we can plug in the values into the formula for beat frequency:
beat frequency (Hz) = | 0.3 m/s | / 0.000616 m
= 487.8 Hz

Therefore, the beat frequency in Hz of ultrasound reflected from an oncoming bloodstream moving at 30 cm/s with an original frequency of 2.5 MHz is 487.8 Hz.

## 1. What exactly is ultrasound?

Ultrasound is a type of sound wave that has a frequency higher than the upper limit of human hearing, which is around 20,000 Hz. It is used in many medical and industrial applications, such as imaging, surgery, and cleaning.

## 2. How is the frequency of ultrasound measured?

The frequency of ultrasound is measured in hertz (Hz), which is a unit of frequency equal to one cycle per second. This means that the frequency of ultrasound is the number of sound waves that pass through a point in one second.

## 3. What determines the beat frequency of ultrasound?

The beat frequency of ultrasound is determined by the difference in frequency between the two sound waves that are interacting. It is the difference between the transmitter frequency and the receiver frequency.

## 4. Can the beat frequency of ultrasound be changed?

Yes, the beat frequency of ultrasound can be changed by adjusting the frequency of either the transmitter or the receiver. This is often done in medical ultrasound imaging to produce different images of the same area.

## 5. What is the typical beat frequency of medical ultrasound?

The typical beat frequency of medical ultrasound ranges from 1 to 15 MHz (million hertz), depending on the type of imaging and the depth of the tissue being imaged. Higher frequencies are used for superficial imaging, while lower frequencies are used for deeper imaging.

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