The teams use convection created by hairdryers to keep bags in the air and than negotiate an obstacle course. The Lab Rats use the same principle to make a giant solar balloon. Will the sun's heat be enough to help their balloon lift up, up and away?

The theme is air pressure: the teams must place a postcard across a cup of water and turn it upside down, allowing air pressure alone to prevent spillage, and then navigate an obstacle course. The Lab Rats then try to crush steel barrels with air pressure!

The crew looks at centrifugal force. The teams have to navigate an obstacle course while keeping a ball spinning round a funnel. Meanwhile, a specially trained Lab Rat tries to create a fire tornado.