Help me with question 8 please :(

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

With i really need the correct answer!

A3.9 g aluminum foil ball with a charge of +4.1×10−9 c is suspended on a string in a uniform horizontal e⃗ field. the string deviates to the right and makes an angle of 30∘ with the vertical. part a part complete what information about the e⃗ field can you determine for this situation? what information about the field can you determine for this situation? only the magnitude of e⃗ only the direction of e⃗ both the magnitude and the direction of e⃗ none of the above previous answers correct part b determine the magnitude of the electric field. express your answer with the appropriate units. e e = nothing nothing request answer part c determine the direction of the electric field. determine the direction of the electric field. to the right to the left away from you toward you