Which describes the average velocity of a unicycle going around in circles? check all that apply!

a. the total displacement divided by the time.

b. every time the unicycle returns to its starting point, the average velocity equals zero.

c. the slope of the acceleration vs. time graph.

d. the average acceleration divided by the time.

Jenny and fred both play a long note on their trombones. a stationary observer hears the sound increasing and decreasing repeatedly in loudness. which of these must be true? the sound waves from the two trombones have slightly different frequencies.the sound waves from the two trombones have the same frequency.the sound waves from the two trombones have slightly different amplitudes.the sound waves from the two trombones have the same wavelength.the sound waves from the two trombones have slightly different velocities.  lolthe answer is          the sound waves from the two trombones have slightly different frequencies.