Look at the image on the left. Describe how the hydraulic jack works. Fluid is pumped into the piston and valves prevent its escape. This fluid generates pressure and lifts the load piston.

In which direction does the water flow? From the water reservoir into the effort piston, then into the load piston and finally back into the reservoir.

What is the purpose of valves? To keep fluid flowing in one direction

Where in Nature are valves used? In the heart and in the blood vessels of animals.

Insert Open or Closed in the table below.