In a hydraulic device, the surface area of the small piston is 1 cm2 and the surface area of the large piston is 8 cm2. If 10 N of force is put on the small piston, how much force will be exerted on the large piston.

You throw a small rock straight up from the edge of a highway bridge that crosses a river. the rock passes you on its way down, 7.00 s after it was thrown. what is the speed of the rock just before it reaches the water 28.0 m below the point where the rock left your hand? ignore air resistance.