PRESSURE <ul><li>In this presentation, you will learn about: </li></ul><ul><li>What is pressure? </li></ul><ul><li>What happens to pressure as we go at a higher or lower altitude? </li></ul><ul><li>How can pressure be increased or decreased. </li></ul>
<ul><li>P ressure is defined as the force per unit area exerted against a surface by the weight of air above the surface at any given point in the Earth's atmosphere . </li></ul><ul><li>In other terms, it is the mass of air acting on humans above the Earth’s crust. </li></ul>WHAT IS PRESSURE?
What happens to pressure when altitude is increased or decreased? <ul><li>The pressure in a high altitude is different from the pressure in a low altitude, for example in the sea. </li></ul><ul><li>At a higher altitude, the atmospheric pressure is less than at a lower altitude. </li></ul><ul><li>Pressure is caused by the weight of air, and therefore the higher you go, the less amount of air, and less pressure. </li></ul><ul><li>The instrument at the back is a pressure gauge which is used to measure pressure. </li></ul>
Notice the decrease in pressure as altitude increases Pressure at different altitudes 4 71000 66 51000 110 47000 868 32000 5474 20000 22632 11000 101325 0 Pressure / Pascal Altitude above sea level / meters
How can pressure be affected? <ul><li>As I had mentioned before, when altitude is increased, pressure will drop, but when it is decreased, pressure will increase. </li></ul><ul><li>Therefore, in order to increase pressure, a person should move downwards and for pressure to increase, a person should move upwards. </li></ul><ul><li>The picture at the back of this slide is that of a world map showing the atmospheric pressure of different regions. </li></ul>
<ul><li>A pressurized aircraft is an aircraft in which air has been compressed into. If an unpressurized aircraft goes over 3,000m above the Earth, people will fall unconscious. </li></ul><ul><li>This is because people can not live in such low pressure, as there is a lack of oxygen. </li></ul><ul><li>This applies to a diver as well. A diver can only reach a certain depth in water, otherwise the pressure will be too much. </li></ul>Pressure suitable for human
<ul><li>Thank you for your attention and I hope that you have learned more on Pressure. </li></ul>THE END
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