PLEASE HELP ME RIGHT AWAY, ITS DUE NOW PLEASE HELP ME

Apiano tuner uses a tuner to create a tone of 5.00 x 10² hz. when a key on the piano is struck he hears 5 beats per second. what is a possible frequency of vibration for the piano string? 2500 hz 1300 hz 605 hz 495 hz

Matter is needed to transfer thermal energy bya. conductionb. convectionc. radiation d. both a & b.

Lightning is an example of what phenomenon? a release of a large amount of energy an absorption of a large amount of energy a natural electric circuit a natural electric current