What is the beat frequence in Hz of ultrasound

[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.)

 

[learningphysics]

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).

Careful with your units.

 

[thepatientmental]

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.