PRESSURE

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PRESSURE
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PRESSURE
a force
-Pressure is __________ pushing on a surface
divided by the ______ of that surface.
Pressure ------------ P ---------
Force is measured in ______ ( ) Area is
measured in __________ ( ) A Newton per
square meter (N/m2) is equal to one ____________
( )
area
F
Force
F
Area
A
P
A
x
Newtons
Square Meters
2
N
m
Pascal
Pa
-When wearing snowshoes you can walk without
sinking. Since your weight is the same whether
you wear the boots or snowshoes, whats the
difference? ______________________________________
_________________________ ________________________
_______________________________________
The force of your body weight is spread (divided)
over a larger area
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Sample Problem A baseball strikes a catchers
mitt with a force of 200N. If the area the ball
strikes is 0.03 m2, what is the pressure exerted
on the mitt?
F
P

A
6666.7 Pa
P
200 N
P
0.03 m
2
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Pressure Gases - Gas particles are constantly
_____________. -Gases naturally have a lot of
______________ between the particles.
in motion
empty space
-Particles exert a pressure out -The
pressure results from the particles
____________ with the walls of the container.
colliding
THE PRESSURE RULE If areas of different
pressures are present they will always try to
________________. To do this ________ pressure
will always move towards ________ pressure.
equalize
high
low
HIGH
LOW
THE PRESSURE RULE ________ TO _________
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-To ? Pressure of a gas ? (add) more
___________ to (This is like when you
pump up a ball)
particles
-To ? Pressure of a gas ? __________
to - This is called _______________ a
gas.
volume
compressing
-Boyles Law states when the pressure of a gas
increases, its volume ___________. When the
pressure of a gas decreases, its volume
___________.

decreases
increases
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gravity
-Gas particles in the air are pulled towards the
Earth by ___________. -These gas particles
stacked upon each other layer after layer form
our ___________________ and produce
__________________ pressure. -Atmospheric
pressure at sea level is (GREATER or LESS) than
the atmospheric pressure in Denver which is 1.6
km above sea level.
atmosphere
atmospheric

(HINT Think what its like in a swimming pool at
the surface and at the bottom)
(Low Pressure)
(High Pressure)
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-The pressure on your hand from the
atmosphere is around ________ N, so why cant
you feel it?
1000
because the pressure is equal on all sides of
your hand and your body used to it.
-To ? Pressure of a gas ? (add) _____________
to
heat
-This causes the particles to ________
________ and have more violent ___________.
move
faster
collision
-Charles Law states When the temperature of a
gas ____________, its volume _____________.
increases
increases
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-According to Bernoulli, the faster a fluid
moves, the less ____________ -Bernoullis
Principle the pressure exerted by a moving
stream of fluid is less than _____________________
_______________________
pressure
the pressure of the surrounding fluid
(In other words Fast moving air creates low
pressure)
-Bernoullis principle is the basis behind a
simple wing. Does the air move faster on top of
the wing or on the bottom of the wing?
___________ How does help the wing lift
up? _________________________________ ____________
_____________________
top
high pressure below the wing
pushes up to get to the
low pressure above the wing
(HIGH to LOW)