The platform is rotating about the vertical axis such that at any instant its angular posi...

The platform is rotating about the vertical axis such that at any instant its angular position is θ = (4 t3/2) rad, where t is in seconds. A ball rolls outward along the radial groove so that its position is r = (0.1 t3) m, where t is in seconds. Determine the magnitudes of the velocity and acceleration of the ball when t = 15 s.