your little sister wants a sled ride on a horizontal fricitonless surface. Starting from rest, you push her 10m with a force of F=60N at an angle of 30 degrees below the horizontal. Your sister + the sled has a mass of 40Kg. How much work is done by the normal force? How much work is done by your push force F? Use the energy method to determine the velocity of the sled after you push it for 10m.