Oct 31, 2011· In a hydraulic lift, the radii of the pistons are 2.50 cm and 9.4 cm. A car weighing W = 8.6 kN is to be lifted by the force of the large piston. (a) What force Fa must be applied to the small piston? (b) When the small piston is pushed in by 8.6 cm, how far is the car lifted? (c) Find the mechanical advantage of the lift, which is the ratio W / Fa.