The uv light that is responsible for tanning the skin falls in the 320-nm to 400-nm region. calculate the total energy (in joules) absorbed by a person exposed to this radiation for 2.5 h, given that there are 2.0 × 1016 photons hitting earth’s surface per square centimeter per second over a 80-nm (320-nm to 400-nm) range and that the exposed body area is 0.45 m2. assume that only half of the radiation is absorbed and the other half is reflected by the body. (hint: use an average wavelength of 360 nm in calculating the energy of a photon.)

1. what is the relationship between wavelength and the penetrating power of an electromagnetic wave? a) the penetrating power has no relationship to the wavelength. b) the penetrating power increases as the wavelength increases. c) the penetrating power decreases as the wavelength increases. d) the penetrating power decreases as the wavelength decreases. 2. as ice melts and turns into water, the speed of sound through the material would most likely do what? justify your answer. a) the speed would not change because the material is always water. b) the speed of sound would increase because the density of water is less than that of ice. c) the speed of sound would increase because energy is added to ice in order to make it melt. d) the speed of sound would decrease because sound travels faster through solids than liquids. 3.which of these waves need a medium to travel through? a) sound b) x-rays c) infrared rays d) visible light