Final answer:
To determine the beat frequency in a Doppler ultrasound of a bloodstream moving at 30.0 cm/s with a source frequency of 2.50 MHz, the Doppler shift formula is applied. However, specifics regarding the blood flow direction are required to perform this calculation, and the provided information is insufficient for a precise answer.
Step-by-step explanation:
The calculation of the beat frequency in a Doppler ultrasound involves the change in frequency of the ultrasound waves caused by the motion of the blood cells. The sweep speed mentioned in the question is not provided but typically relates to the display speed of the ultrasound machine's output, which does not directly impact the calculation of the beat frequency. To find the beat frequency due to the Doppler effect when ultrasound of frequency 2.50 MHz is reflected from a bloodstream moving at 30.0 cm/s, where the speed of sound in human tissue is 1540 m/s, we would employ the Doppler shift formula.
However, as the given information does not specify the direction of blood flow relative to the sound wave source, we cannot calculate a specific beat frequency without making additional assumptions. Assuming the frequency of 2.50 MHz is accurate to seven significant figures, a precision that implies high accuracy in measurement and calculation in Doppler ultrasound studies.