A 560 Hz tuning fork and a piano key are struck together, and four beats are heard. When a 572 Hz tuning fork and the same piano key are struck, eight beats are heard. What is the frequency of the piano key? 564 Hz
556 Hz
572 Hz
560 Hz

556

Explanation:

the earths atmosphere is made up of nitrogen and oxygen. solids can turn into gasses through a process called sublimation. sublimation is the transition of a substance directly from the solid to the gas phase, without passing through the intermediate liquid phase.

hope this : d