A motor operating on 245 V electricity has a 172 V back emf at operating speed and draws an 11.6 A current. (a) What is its resistance (in Ω)? Ω (b) What current (in A) does it draw when it is first started? A †

Describe the path of a ray that approaches a mirror parallel to the principal axis.

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.

How does changing the frequency affect the energy of the wave?