4. Superman (m = 50 kg) is running to save the day! He needs to reach the top of a circular curve (R = 5 m). Superman notices that there is a sled sitting at rest a distance x = 5 m from the bottom of the curve. On the flat surface, the coefficient of friction between the surface and the sled is k = 0.2. On the curve, there is no friction between the curved surface and the sled. See the figure below denoting these values.

R =5m Ax = 5m H = 0 m = Skg aled H = 0.2