A: is potential
C: is losing kinetic energy and gaining potential energy
B: kinetic energy is at its highest
D: is loosing potential energy and gaining kinetic energy
A beat is an interference pattern between two sounds of slightly different frequencies, perceived as a periodic variation in volume whose rate is the difference of the two frequencies. Frequency beat is equal to,

The reference frequency in our case would be 392Hz, and since there is the possibility of the upper and lower range for the amount of beats per second that the two possible frequencies are heard would be


Therefore the two possible frequencies the piano wire is vibrating at, would be 396Hz and 388Hz
Answer:
Matter can be changed, but not created or destroyed.
Explanation:
Matter can change for through physical and chemical changes, though this happens, matter is conserved. The same amount of matter exists before and after the change.