The input piston and output plunger of a hydraulic car lift are at the same level, as shown in the drawing. The cross-sectional area of the input piston is 12 cm2, while that of the output plunger is 1200 cm2. The force F1 applied to the input piston has a magnitude of 140 N. What is the weight W of the car? Neglect the weight of the piston and plunger. Give your answer to two significant figures, e.g., 640 N.
Since the pistons have an area ratio of 1:100 then a force of 140 Nt will on the small piston will lift 14000 Nt on the large piston. Of course it will only lift it 1/100th as far as you push the small piston.
The ratio of the areas of the pistions is 1 to 100, this ratio is the same for the force. The for of 140 N is changed a force of 14,000 N on the other pistion, but it will only be lifted 1/100th of the distance. Long story short according to your problem the car weighs 14,000 N or 1.4 times 10^4
