temperature
density
Hot air rises.
Hot air rises.
It doesn't actually rise, so much as it does float on top of cold air. Think of it this way: If someone was floating in a pool, and we poured more water in the pool, did that person rise? They didn't actually do anything other than float there. Heat is the same way. It's not actively moving when it "rises".
Hot air is less dense (lighter) than colder air, so warmer air will naturally rise above the cooler air.
The air density inside a balloon changes as it rises because the hot air inside the hot air balloon is less dense than the air around it causing it to fly since hot air rises. But as it rises it loses its hot air causing it to eventually not be able to fly anymore and come down.
Hot air rises because it is less dense than cold air.
Hot air is lighter than cold air, so it rises up. Ex. A hot air balloon rises up because we heat the air and it goes up.
No, a hot air balloon rising is a physical change, not a chemical change. The balloon rises because the air inside it is heated, causing it to expand and become less dense than the surrounding air, which causes it to float upwards.
because hot air rises
because it is lighter and less dense
A hot air balloon flies because it is filled with hot air. Hot air rises and causes the balloon to lift from the ground.
"Warm air", otherwise known as Hot Air Balloons, float because of one basic Law of Thermodynamics; heat rises. The air in a hot air balloon is hot, therefore, the balloon rises.
hot air rises because molecules of air move quicker
My guess is that it's because smoke is hot. Hot air rises, just as cold air sinks. When a fire ensues, smoke (the product of carbon combustion) rises with the hot air.
because its evaporating
Because hot air rises and cool air sinks. the reason why is because hot air is less dense than cool air so the cooler air will sink