Geography 1900 Lecture 5

Front 1

mass

Back 1

amount of matter contained in many objects,

Front 2

pressure

Back 2

force per unit area
to create pressure we apply force

Front 3

force

Back 3

m x a
horizontally: think car, gas pedal, brakes
vertically: think falling objects and gravity

Front 4

atmospheric sea level pressure

Back 4

due to the mass of the atmosphere and the acceleration of gravity pulling down on it at earth's surface

Front 5

force of gravitation

Back 5

mass of air x gravitational acceleration

Front 6

bathroom scales

Back 6

remove gravity from final value

Front 7

you make a barometer every time you drink from a straw

Back 7

we are not pulling the fluid into the straw
we are creating a vacuum
higher atmospheric pressure is pushing the fluid up the straw

Front 8

reasons atmospheric pressure decreases w/ height

Back 8

atmospheric pressure at a given level in the atmosphere is the gravitational force of all the air above that point per unit area

Front 9

vertical pressure gradient

Back 9

atmosphere is compressed by gravity but supported by high speed air molecules trying to escape to space

as a result atmosphere has an exponential decrease in pressure with height

the vertical pressure gradient

Front 10

hydrostatic equilibrium

Back 10

balance on earth between gravitation and the natural tendency for air molecules to escape upward

Front 11

what is density

Back 11

density is mass per unit volume

Front 12

atmospheric impacts

Back 12

cold air masses and warm do not mix easily
-they push against each other in part because they resist mixing

Front 13

equation of state

Back 13

pressure, temperature, and density for an ideal gas are related by the ideal gas law
P= mass/volume(dry air x degrees kelvin)

Front 14

equation of state

Back 14

pressure, temperature adn density changes interact with each other