1. How much gravitational potential energy did King Kong have at the top of the Empire State Building? King Kong had a mass of 25×106 kg. The Empire State Building is 381 m (1,250 feet) tall.
2. A rifle can fire a 4.20-gram bullet at a speed of 965 m/s. Calculate the kinetic energy of the bullet after leaves the barrel of the rifle.
3. In 1992, David Engwall of California used a slingshot to launch at 62 g dart. The dart traveled a distance of 477 m (almost 5 football fields). The amount of potential energy in the slingshot was 140 J. If the spring constant of the slingshot is 30000 N/m, how far was the slingshot stretched?