Atmospheric Pressure
Science: KS3, topic 3.5.18
Atmospheric Pressure
Pressure from the atmosphere is pushing on us from all directions. We don’t feel it though.
Sea level pressure
- At sea level, the atmospheric pressure is on average 100,000 N/m2 (Pa).
- Pressure changes slightly because of temperature and how humid the air is.
Pressure and weather
- High pressure means hot and fresh weather.
- Low pressure means stormy weather.
Height and pressure
- As you increase height, pressure decreases.
- The pressure at the top of Mount Everest is 30,000 N/m2 (Pa).
Oxygen at height
- The drop in pressure with height also causes a lack of oxygen.
- The lack of oxygen is why mountaineers carry oxygen when they climb Mount Everest.
Aeroplanes and pressure
- Pressure drops with height, so planes must be pressurised.
- Pressurising keeps the air inside a plane close to sea level pressure.
Test yourself on Atmospheric Pressure
Why are planes pressurised?
Select the correct statement in each pair
The air pressure at the summit of Mount Everest is 30,000 Pa. At sea level, the air pressure is 100,000 Pa. Who is at the greater height: a climber at the summit, or a person at sea level?