Grandpa Fenn's Workshop
The Hot-Air Balloon
Grandpa has sewn a balloon as big as a barn. It has no engine. It has a burner, a basket and a lot of patience.
Grandpa Fenn's Workshop
Grandpa has sewn a balloon as big as a barn. It has no engine. It has a burner, a basket and a lot of patience.
Choose who rides along. Turn the burner up. Heat the air, then watch what happens.
The balloon settles onto the hillside with barely a bump. Flicker jumps out first and rolls in the grass.
Hot air is lighter than cool air. Heat the air inside the balloon and it stops weighing as much as the air around it. The balloon floats up the way a cork floats up in water.
It does not rise at once. The air takes time to heat. And it takes time to cool. A pilot learns to give a little heat and then wait.
The higher the balloon goes, the thinner the air gets. So it rises until the lift and the weight match. Then it floats.
Grandpa checks the burnerHot air is lighter than cool air.
Heat makes the balloon rise. Cooling lets it sink.
A heavier load needs more heat.
Big word for the day. Buoyancy. The upward push a lighter thing gets from the heavier air or water around it.
More machines are waiting on the bench.
Back to the Chain Reaction Bench