Beat frequency from ultrasound reflected by moving blood

[cyberdx16]

Homework Statement

Ultrasound reflected from an oncoming bloodstream that is moving at 38 cm/s is mixed with the original frequency of 1.3 MHz to produce beats. What is the beat frequency? (Velocity of sound in blood = 1540 m/s.)

Homework Equations

Fo=Fs(v+Vo/v)
Fb- (F2-f1)

The Attempt at a Solution

idk where to start...

 

[mjsd]

you are given the original freq... need to work out the reflected freq first... which would be doppler shifted due to moving source... I think you have got your two relevant equations written down.

 

[cyberdx16]

so Fobserver is 1300000Hz, Vsource is .38m/s, and Vobserver is 1540 m/s?

so i would do 1300000=Fsource (345 + 1540/345-.38)

take this # and subtrack by 1300000?