Atmospheric Pressure Flashcards

All 6 cards in this deck

In a simple model, what is the Earth's atmosphere?

A thin layer of air surrounding the Earth — thin compared with the size of the Earth.

What causes atmospheric pressure on a surface?

Air molecules colliding with the surface.

What happens to the density of the atmosphere as altitude increases?

It decreases — the air gets less dense higher up.

As the height of a surface above ground level increases, what happens to the number of air molecules (and so the weight of air) above it?

It decreases, so the atmospheric pressure on the surface decreases.

True or false? Atmospheric pressure at the top of a mountain is the same as at sea level.

False. It is lower, because there is less air above the surface at greater height.

True or false? Atmospheric pressure pushes only downwards on a surface.

False. The pressure of a fluid produces a force normal to any surface, whatever its orientation.