1) At the 2004 Olympics Games in Athens, Greece, the Iranian athlete Hossein Reza Zadeh won the super-heavyweight class gold medal in weightlifting. He lifted 472.5 kg (1041 lb) combined in his two best lifts in the competition. Assuming that he lifted the weights a height of 208.3 cm, what work did he do?
2) A stone (mass = 0.3 kg) is dropped from height 10 m in Earth's gravity, with initial velocity 0. Calculate its kinetic energy when it hits the ground.
3) Calculate the kinetic energy of a car (mass = 1000 kg) moving 20 miles per hour.