Beakman explains how gas is explosive and causes the combustion engine in the car to work. He uses a model engine with a side view and demonstrates what is happening with the gasoline when it explodes to move the engine parts. Beakman shows how the engine allows the wheels to turn by relating it to riding a bike. Up and down motion of the pedals is converted to turning the wheels through the chain. Same in the car with the pistons turning gears and thus the wheels.

Beakman explains what a submarine is and how buoyancy and density affect a submarine rising and sinking. Then he makes a DIY submarine from a soda bottle.

The Rocket Boys run several tests in order to perfect their rocket design. They use the launch results as feedback to help them refine their design.

Larry learns that Mrs. Tainot is playing music to drown out the GPS voice, which never stops. He then helps her turn off the "auto-on" feature on the very complicated GPS, which has no shortage of menus, submenus, and confirmation prompts.

Beakman explains how a helicopter has a rotating wing on top that helps it stay up because of the air pressure difference created by the shape of the wing. Then he explains that the back propeller helps steer the helicopter.