A car has a mass of 1 200 kg. A very strong weightlifter attempts, unsuccessfully, to lift the car by applying an upward force of 2 500 N. What is the normal force acting on the car as the weightlifter is applying this force? Be sure to include a force diagram in your answer.

Suppose that a cylindrical tank 6 meters high with a radius of 2 meters is filled to the rim with water. the tank is buried so that the top of the tank is 1 meter below ground level. the space above the tank is not filled with water. calculate how much work needs to be done by a pump to pump the water out of the tank up to ground level. (the water weighs 9,800 newtons per cubic meter.)