How would i turn the formula (1/2)mv^2=mgh into a formula to find final velocity?

What would the difference of spectral lines emitted by hydrogen gas in distant galaxies which is normally found at a wavelength of 21 cm on earth, be observed at 21.1 centimeters?

Determine the maximum r-value of the polar equation r =3+3 cos 0

What is a carrier wave and how does it affect what you hear on the radio