A snowboarder with a mass of 78.4kg arrives at a bottom of the hill and glides across a horizontal stretch of ground to a lift line which is 38.5m from the bottom of the hill. friction exerts a force with a magnitude of 95.0N on the snowboarder so that he arrives at the lift line with a speed of 1.60m/s. What was the kinetic energy of the snowboarder at the bottom of the hill