1-) A 56.0kg cheerleader uses an oil-filled hydraulic lift to hold four 110kg football players at a height of 1.30m. If her piston is 19.0cm in diameter, what is the diameter of the football players' piston?
2-) A 0.500m -diameter vat of liquid is 2.20m deep. The pressure at the bottom of the vat is 1.30atm. What is the mass of the liquid in the vat?