Why does warm air rise?

Question

I need help on this question badly thanks!

Answer 1

because it has work to do - cant stay in bed all day you know !

Answer 2

The previous answers are good answers to this question. Here is my way of explaining it: When you add heat to air (or any other material for that matter) you cause the atoms to become more energetic which makes it less dense. (They need more elbow room when they're dancing, so you have the same amount of material taking up more space, making it less dense) When you combine a less dense material with something more dense, the less dense material will fall because gravity acts on it with greater force. The warm air really isn't so much rising, rather, the cooler air is falling and the warm are moves up to establish an equallibrium in pressure.

Answer 3

Warm air rises because heat causes the molecules to expand. This allows more air between them and effectively makes it lighter than cold air.

Answer 4

Warm air rises because it it less dense. The higher temperature causes the molecules to move further apart due to a gain in kinetic energy which results in this lower density.

Answer 5

Warm air rises simply because the molecules weigh less that cold air. With cold air the microscopic molicules of water freeze and weight the air down while in hot air the molecule remain unfrozen and are allowed to rise. Hope that helps.

Answer 6

The molecules are movig faster and so farther apart, so that means that it is less dense. Density is how close the molecules are. Less dense air will rise, compared to denser air which sinks. If you stand in front of a refrigerator, barefooted, you can feel the cool air falling.

Answer 7

Heat causes molecules to expand; so fewer molecules take up same amount of space than cooler air molecules - therefore there are fewer molecules in the warm air - therefore it's lighter... does that make sense?

Imagine 5 molecules taking up the same amount of space as 10... obviously the 5 will be half the weight of the 10...

Better?

Answer 8

As it warms, the air molecules push against each other harder, pushing them further apart. Thus, the same mass of air (which by definition has weight) takes more space and thus it "floats" on top of denser air.

Answer 9

when air is heated the warm air particles expand and move quickly, that causes them to rise.

Answer 10

Because it's less dense than cold air. Cold air can contain moisture which makes it sink.

Answer 11

because cold air is more dense and sinks below warmer air forcing it to rise