A 50 kg kid swings on a swing with a length of 5 m. At the bottom, she has a velocity of 3 m/s. What is the force of tension in the swing at the bottom?

90 N
400 N
580 N
830 N

PLEASE HELP IM TAKING MY FINAL

Ultraviolet radiation is dangerous because it has a high enough energy to damage skin cells. what is the best explanation of the relationship between wavelength and wave energy? a) wave energy is related only to frequency, not wavelength. b) longer wavelengths have lower frequencies but higher energy. c) the shorter the wavelength, the lower the frequency and the higher the energy. d) the shorter the wavelength, the higher the frequency and the higher the energy.