Pressure Flashcards
exerted whenever a force is applied over an area
pressure
the force acts over a small area and so produces a _
high pressure
the force acting over a larger area produces _
lower pressure
force per unit area
pressure
the formula in getting pressure
force/area
measures the pressure
N/m^2 (newtons per square meter) or pascals (Pa)
can also be measured in
newtons per square millimeter/centimeter
N/mm^2) or (N/cm^2
Pressure depends on two things
- how much force is applied
- how big the area on which the force is applied
in liquids, pressure _ with depth
increases
in liquids, pressure acts _ in all directions
equally
the pressure caused by a column of liquid can be calculated using the equation:
pressure = height of column x density of the liquid x gravitational field strength
pressure = hpg
density is measured in _
kilograms per meter cubed (kg/m^3)
gravitational field strength is measured in _
newtons per kilogram (N/kg)
it is caused by the weight of all the air in the atmosphere pressing down on earth
air pressure
air pressure is also known as _
atmospheric pressure
air pressure changes with the height and also when air _ or _
warms up, cools down
changes in air pressure causes changes in the _
weather
when air rises, it leaves behind an area of _, because the upward-moving air is not pressing down hard on the surface
lower pressure
areas of _ are formed where air is sinking back down, and so pushing down harder
high pressure
there are many areas of high and low pressure above the Earth’s surface due to _
uneven surface heating
air moves from higher to lower pressure area forming _
winds
areas of low pressure with the lowest pressure at the center; usually brings wet, cloudy weather
lows
areas of high pressure with the highest pressure at the center; brings sunnier and dryer weather
highs
A device used to measure atmospheric pressure.
It was invented in 1643 by Italian scientist Evangelista Torricelli (1608-1647)
barometer
The SI unit of pressure
pascal
Another unit of pressure commonly used in engineering and used for measuring tire pressure is _
pounds per square inch (psi).
result of the mass of air being pulled toward the center of the earth by gravity
atmospheric pressure
the higher the elevation, the _ the air
lesser/thinner
expressed based on the height of the mercury inside the column that the gas pressure can support
units of pressure
the unit _ is also known as torr, in honor of Torricelli
mmHg (millimeters of mercury)
