A scuba diver descends to a depth of 20m. At that depth, thepressure is approximately A)atmospheric pressure.
B)twice atmospheric pressure.
C)three times atmospheric pressure.
D)four times atmospheric pressure.
Hint:
P = P0 + rho*g*h Do not forget P0, the atmosphericpressure.

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