What simple machines is being shown in this photo ? 1. pulley
2. incline plane
3. wedge
4. wheel and axle
5.screw
6.lever

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.)