A 39 kg boy runs with a velocity of 3.8 m/s. How much kinetic energy does he have? Then he grabs on to a rope that is hanging from the ceiling, and swings from the end of the rope. How high off the ground will he swing?

Amass weighing 24 pounds, attached to the end of a spring, stretches it 4 inches. initially, the mass is released from rest from a point 8 inches below the equilibrium position. find the equation of motion. (use g = 32 ft/s2 for the acceleration due to gravity.)