A 1–kilogram block slides down a frictionless inclined plane 2.5 meters high. What is its velocity at the bottom of the plane? (Assume gravitational acceleration is 9.8 m/s2.) A. 2.5 m/s B. 3.9 m/s C. 7.0 m/s D. 9.8 m/s

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.