Science!!!!!!!!!!!!!!!!!! Help!!!!!!!! :(?

Question

1) Explain how a hot air balloon rises in terms of density.
2) What role does gravity play in whether or not an object that floats?
3) What gas was used in Hindenburg? What gas is used in today's blimps?

Answer 1

1)Hot air is less dense, the particles are more spread out. The balloon will rise because things that are less dense rise in areas where there is high density. Like an air bubble in water.

2)Gravity plays no role in floating objects...it's all about density of water and density of the object.

3)Hydrogen was used in the Hindenburg and it's highly flammable...which is why it exploded. Helium is used in today's blimps which is a heck of a lot safer.

Answer 2

1. Hot air is less dense than cool air. A hot air balloon will be less dense than the cool air it displaces, and will rise buoyantly.

2. Gravity plays no role in density. Its only role in flotation would be to provide an "up" and a "down" reference -- can't float on top of something unless there's an "up."

3. Hydrogen was used in the Hindenburg. Helium is used in most blimps today. Helium doesn't burn, and doesn't react with rubber or cloth. The downsides to helium are: it's heavier than hydrogen, and it can slowly diffuse through a rubber membrane.