Amerry-go-round is a common piece of playground equipment. a 3.0-m-diameter merry-go-round, which can be modeled as a disk with a mass of 230 kg , is spinning at 17 rpm. john runs tangent to the merry-go-round at 4.2 m/s. what is the merry-go-round's angular velocity, in rpm, after john jumps on?

When a vertical beam of light passes through a transparent medium, the rate at which its intensity i decreases is proportional to i(t), where t represents the thickness of the medium (in feet). in clear seawater, the intensity 3 feet below the surface is 25% of the initial intensity i0 of the incident beam. what is the intensity of the beam "10" feet below the surface? (give your answer in terms of i0. round any constants or coefficients to five decimal places.)