Hydraulics Demo





A good way of demonstrating the basic principles of hydraulics is to join
two syringes together with rubber tubing to make an watertight seal.[see
figure 1]The syringes can be filled with water, oil, or just air. Pushing
plunger A causes plunger B to move out and pushing plunger B in causes
plunger A to move out. This works even if the syringes are not in the same
plane. i.e. if the tubing is bent by 90° as long as there is no kink in
the tube that prevents the free flow of fluid.

By adjusting the size of the syringes it is possible to demonstrate how to
multiply force [see figure 2]. A small mass on a small syringe can lift a
much larger mass if it is resting on a bigger syringe. This is because the
pressure in the two syringes is equal, but the surface areas of the two
pistons are different, and force = pressure × area.