Beakman demonstrates force and pressure with a balloon sitting on one nail with a brick on it (it pops) and then how it doesn't pop if you have more nails to distribute the pressure of the force. He shows how this also applies to cutting a tomato. Then Beakman lays on a bed of nails to prove it.
Beakman explains that construction equipment is "strong" because of hydraulics. He demonstrates that when you try to compress a liquid, it has a limit. Pascal's principle says that the pressure is the same everywhere in the liquid so if you open the end of the syringe, then the liquid is forced out. Using this, they show how Liza can push down on one hydraulic shaft and this will cause the rat to be lifted. Basically, she does more work with less energy.