Q. A 8 m x 11 m swimming pool slopes linearly from a 1 m depth at one end to a 3.8 m depth at the other. What is the mass of water?
Q. An airtight box has a removable lid of area 1.5 x10-2m2 and negligible weight. The box is taken up a mountain where air pressure outside the box is 0.65 x10^5Pa. The inside of the box is completely evacuated. What is the magnitude of the force necessary to pull the lid off the box?