Pressure in the Scientific Sense

Pressure is force/area. A force is a push or pull. An area is represented by a value squared. Some units of pressure obtained from Pressure , from Wikipedia the free encyclopedia are psi (pounds per square inch), torr, millimeters of mercury (mmHg), pascal, and atmosphere (atm). At ground level air pressure is about 1 atm or 14.7 psi. Pressure changes with altitude.

Air pressure depends on the gases that make up the atmosphere. The Earth's atmospheric composition of gases by volume found at Pressure , from Wikipedia the free encyclopedia is as follows: 78 % nitrogen, 21 % oxygen, 0.9 % Argon, 0.04 % CO2, and minor levels of other gases. The mass of the combined total of these gases multiplied by Earth's gravity and divided by the area over which they act results in air pressure. The moon has no atmosphere. So, there is no air pressure on the moon.

Pressure decreases with elevation. When moving from lower elevations to higher elevations, you might feel dizzy. This is because of the decreased air pressure, resulting in less oxygen entering your lungs. Less oxygen in the blood results in fatigue. It takes time for your body to adjust by generating a higher amount of red blood cells to capture more oxygen. So, after time, the fatigue will go away.

When you are in an airplane, the pressure inside the plane is greater than outside. If a window broke in the airplane, objects would be sucked out, because of the greater pressure in the plane and lower pressure outside. This would result in objects being pushed out of the plane.

Pressure increases with depth. In water as you descend pressure increases. When you're in water, you have to add the air pressure + water pressure. If you were to descend in water the pressure would build with depth. This is why a submarine can only travel to certain depths in water, otherwise it risks implosion.

Boxers, wear gloves, because the gloves decrease the pressure on their hands. The force of their punch remains the same, but the pressure changes with a glove. The boxing glove surface has more area than the front of the fist, resulting in less pressure. Remember, pressure is equal to force/area. If the denominator (area in this case) is larger then pressure is smaller. Since the boxing gloves have more area, the boxer's hands feels less pressure.

Pressure depends on elevation. It can explain why someone gets dizzy when he changes his elevation, or why a boxer does not break his hand with a glove.

Source

Pressure , from Wikipedia the free encyclopedia, Wikipedia