The Space Shuttle travels at a speed of about 7.70 103 m/s. The blink of an astronaut's eye lasts about 115 ms. How many football fields (length = 91.4 m) does the Shuttle cover in the blink of an eye?

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 1.90