Forces and Matter (15) Flashcards
Why does atmospheric pressure vary with height?
The atmosphere is a layer of air that surrounds the Earth. As you increase in altitude, the density of the air decreases meaning there are less molecules colliding with a surface at higher altitudes. In addition, there are less molecules above you so there is less weight of air contributing to atmospheric pressure.
What does pressure in a fluid depend on?
Depth and density. The deeper you are in a fluid the more weight of the fluid and the atmosphere is above you, increasing the pressure. Being in a more dense liquid means that there are more particles colliding with you exerting a pressure on you.
In what direction does pressure in fluids exert on a surface?
Pressure in fluids cause a force normal to any surface.
How is pressure related to force and area?
Fluid pressure is exerted due to collisions of gas or liquid particles exerting a force on the surface. If the area of the object the fluid is in contact with is small, the pressure will be greater (P (Pascal, Pa) = F/A).
What equation links pressure, height of column, density of fluid and gravitational field strength?
P (Pressure, Pa) = h (height, m) x p (density, kg/m3) x g (gravitational field strength, N/Kg).
