Four cars A, B,C, D of masses 1000kg, 650 kg, 500kg, 2100 kg are running at the same speed of 50 m/s. If all cars are hit from behind with the same force and they continue to move forward, the maximum acceleration will be produced in : 

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.