Solar panels work because photons from the sun give their energy to electronsin the panels. at noon on atypical mid-june day, the power of the visibleradiation from the sun is about 225 watts per square meter. if you had solar panels onyour roof covering an area of 2 meters by 6 meters, and the efficiency of the panel was13% (meaning that 13 out of every 100 photons hitting the panel sent an electron downthe wire), how many electrons per second would you get? (you can take the averageenergy of a solar photon to be that of green light, about 535 nm.)

People with normal vision cannot focus their eyes underwater if they aren't wearing a face mask or goggles and there is water in contact with their eyes. in a simplified model of the human eye, the aqueous and vitreous humors and the lens all have a refractive index of 1.40, and all the refraction occurs at the cornea, whose vertex is 2.60 cm from the retina.with the simplified model of the eye, what corrective lens (specified by focal length as measured in air) would be needed to enable a person underwater to focus an infinitely distant object? (be careful-the focal length of a lens underwater is not the same as in air! assume that the corrective lens has a refractive index of 1.62 and that the lens is used in eyeglasses, not goggles, so there is water on both sides of the lens. assume that the eyeglasses are 2.05cm in front of the eye.)