A spinning top rotates so that its edge turns at a constant speed of 0.63 m/s. If the top has a radius of 0.10 m what is the centripetal acceleration of the edge of the top?

0.016 m/s2
0.73 m/s2
4.0 m/s2
6.3 m/s2

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