The force of gravity acting on a childs mass on earth is 490 newtons whats the childs mass

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.

What is the magnitude of the gravitational force acting on the earth due to the sun?

Due in 40 explain in terms of frame of reference if you’re inside a moving train everything on the outside can seem to be moving