Suppose it were possible to drill a frictionless cylindrical channel along a diameter of the Earth from one side of the Earth to another. A body dropped into such a channel will only feel the gravitational pull of mass within a sphere of radius equal to the distance of the mass from the center of the Earth. The density of the Earth is 5.52 × 103 kg/m3 and G = 6.67 × 10−11 N⋅m2/kg2. The mass will oscillate with a period of
◦ 84.4 min.
◦ 169 min.
◦ 24.0 h.
◦ 1 130 h.
◦ 27.2 d.