If you are given time and distance, you can determine power if you know

a charge 3q is at the origin, and a charge −2q is on the positive x axis at x=a. part a where on the x-axis would you place a third charge so it would experience no net electric force? enter an expression for the exact answer, which will involve a square-root sign. (do not enter an approximate decimal answer.)

coil wire, increase current, put iron inside the coil

it is the second option.

wavelength divides in half and speed stays the same.