Carbon dioxide, sulfur dioxide, chlorine gas
Gas is heavier than oxygen. Cold air is heavir than hot air
global warming
A hot air balloon is normally powered with propane. Other than that, it is just ordinary air used inside the balloon.
Hot air is less dense than the surrounding air and therefore it rises. Cold air, on the other hand, is the opposite. It is more dense than surrounding air and sinks.
If it is warmer than the other air mass, it goes up. This is because warm air is less dense than cooler air, causing it to rise when they meet. This causes clouds and sometimes light and steady precipitation.
only if the air is denser than air.
Cleaner air than the jitterbug.
Most air bags will not deploy at less than 10 miles per hour the other posibillity is that there was a fault in the air bag system.
the induced draft type is more expensive than the other type, however it is often preferred because it is more efficient.
Since air is considered as a fluid, it's a fluid friction and it works the same way as the fluid does.
Wind is caused by uneven heating of the earth by the sun. If the sun were to heat an area of the earth more than another, the air in that area would be warmer than the air in other areas. When this happens the warm air rises and by doing so creates pressure which pushes air back down in another area, which again pushes more air horizontally creating wind.
kinetic friction