When a 480 hz. tuning fork and a piano key are struck together, four beats are heard. when a 470 hz. tuning fork and the same piano key are struck, six beats are heard. what is the frequency of the piano key? unknown piano key = hz

475
476
477
478

If you place a magnet under a clear dish, and sprinkle iron fillings over it, above what part of the magnet will most of the fillings gather

Decreased sensitivity to an unchanging stimulus is known as

Select all the correct answers. which changes will increase the rate of reaction during combustion? decreasing the area of contact between the reactants adding more oxygen to the reaction removing heat from the reaction changing the reactants from solid form to powdered form lowering the exposure of the reactants to air