Bigger difference, faster wind
A bigger pressure difference moves air faster.
Two differences
Air escapes from a balloon when there is a pressure difference between the balloon and the outside air.
When is the escaping air faster?
What this lesson covers
The idea
The greater the pressure difference, the faster the air moves.
Two differences
Air escapes from a balloon when there is a pressure difference between the balloon and the outside air.
When is the escaping air faster?
- When the pressure difference is larger
- When the pressure difference is smaller
- The speed never changes
Compare the difference
Open both tabs.
Speed and difference
If we could measure the speed of the escaping air, we would find that it is higher when the pressure difference is higher. The same is true for winds: a greater pressure difference gives a faster wind.
The greater the pressure difference, the faster the air moves.
Notes
A greater pressure difference makes air move faster.
Check yourself
The speed of the air is higher when the pressure difference is …
Between two places the pressure difference becomes much larger. The wind there becomes …
Two places have almost equal air pressure. The air between them will …
The wind speed depends on the …
- lower. A lower difference gives slower air.
- zero. With no difference the air does not move.
- higher — correct. Yes!
- faster — correct. Yes!
- slower. A larger difference means faster air.
- calm. A larger difference means faster air, not calm.
- move very fast. With almost no difference, the air hardly moves.
- hardly move — correct. Yes!
- rise to the sky. Wind moves along from high to low pressure. With a tiny difference it hardly moves.
- colour of the sky. The pressure difference decides how fast the air moves.
- size of the clouds. The pressure difference decides the wind speed.
- pressure difference — correct. Yes!