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Altitude

physical science Maturity 7-9 Next article →

Altitude is a way to measure vertical distance. It tells us how far something is from a starting point called a datum.

Altitude
Altitude

This starting point can change depending on what you are doing. In geography, people often use the word elevation to talk about height above sea level. In aviation, pilots must be very careful about which datum they use. They might measure from the sea or from the ground below them. Using the right measurement helps everyone stay safe during a flight.

Air pressure changes as you go higher in the sky. This happens because gravity pulls air molecules close to the ground. At high altitudes, there is also less oxygen for living things to breathe.

vertical distances
vertical distances

This can lead to altitude sickness if a person does not adapt. The human body can undergo acclimatization to help with this. This means the heart beats faster and the blood changes to use oxygen better. It can take days or even weeks for the body to adjust.

Pilots use a special tool called a pressure altimeter to find their height.

Boeing 737 view 1
Boeing 737 view 1

This tool is actually an aneroid barometer that shows distance instead of pressure. There are many different types of altitude that pilots talk about. Indicated altitude is the number shown on the altimeter screen. Absolute altitude is the actual distance from the aircraft to the ground below. True altitude is the real height above mean sea level. Pilots also use pressure altitude to talk about flight levels.

Scientists study the different layers of the atmosphere at different altitudes. The troposphere is the layer closest to the Earth's surface. Above that is the stratosphere, where many jet aircraft like the Boeing 737-800 cruise.

Boeing 737 view 1
Boeing 737 view 1

This layer is stable and helps planes avoid bumpy weather. Higher up, there are layers called the mesosphere and the thermosphere. The Kármán line is a special boundary at 100 kilometers. This line marks the point where the atmosphere ends and space begins.

Altitude affects many different things in our world. For athletes, high altitude can be both good and bad. In short sprints, there is less air resistance to slow them down. This can help them move faster during a race. However, for long endurance races, the low oxygen makes it harder to run.

vertical distances
vertical distances

Some athletes use altitude training to help their bodies prepare for big races. This training helps them perform better when they return to sea level.

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File:Altitude.svg
Altitude.svg
File:Boeing 737 view 1.jpg
Boeing 737 view 1.jpg
File:vertical distances.svg
vertical distances.svg
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