A uniform sphere made of modeling clay has radius R=0.34m and moment of inertia I=2.77 for rotation about a diameter. It is flattened to a disk with the same radius . What is the moment of inertia of the disk for rotation about an axis that is at the center of the disk and perpendicular to its flat surface?

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