Chapter 11
Edited by
Destiny Langsford
Madison Sanders
Pressure
Section 1
Pressure is equal to the enforce exerted on a surface divided by the
total area over which the force is exerted. Pressure decreases as the
area which forces are distributed increases. You can also calculate
pressure by dividing force by area . The unit for Pressure is called
Pascal. There are 3 different kinds of pressure, but I am only going
to talk about fluid pressure and the causes of fluid pressure. Fluid
pressure is basically fluid being exerted by force. That being said
liquid can be in different shapes too. Examples of fluid is water,
oil , and gases. The causes of fluid pressure is that when all the
individual partial combine to make up pressure exerted by the
fluid .
Air pressure the massive liquid mass that applies force on everything. Air pressure can cause atmospheric pressure. N/cm2 this is
to see how much atmospheric pressure there is. The high pressure
flows to low pressure. When this happens it makes the containers
structure rumble unless it is able to support that amount of force.
With elevation Pressure can increase or decrease depending on
where it is near sea level. To measure atmospheric pressure you
need a special tool called a barometer. When the atmosphere
presses on it it moves a hand in millibars
Tyler Favors
Graham Payne
Floating and Sinking
Section 2
Buoyancy
Have you ever picked up and object under water and had it feel
lighter than it is out of water? The reason for this is the buoyant
force. The buoyant force is when water and other fluids exert an
upward force on submerged objects that acts in the opposite direct of the force of gravity causing objects to feel lighter. Fluids
exert pressure on all surfaces of submerged objects, and that
pressure increases with depth. The weight of an object is a
downward force. If the weight of the object is greater than the
buoyant force, then there will be a downward net force, and the
object will sink. An object floats when its weight is less than the
buoyant force, because there is an upward net force. When the
object’s weight and the buoyant force are equal, the object will
stay the same due to there not being a net force.
Density
By changing an object’s density, you can make it sink or float.
When the density of an object increases, then the object will
sink. For example, to make a submarine dive, water must be
taken into its tanks causing the submarine’s density to increase.
On the other hand, to make an object float, you must decrease its
density. An example of this would be ice. When you freeze water, the ice becomes less dense, so it floats on the water.
We’ve got jokes!
Why do rocks sink?
They don’t know how to swim!
Hannah Bratcher
Brianna Groves
Rodreeka Jackson
Pascal’s Principle
Section 3
Emilee Bailey
Destiny Langsford
In the 1600s a man named Blaise Pascal (a French mathematician) discovered that when force is applied to a confined fluid the change in pressure is transmitted equally to all parts of the liquid. This became known
as PASCAL'S PRINCIPLE, you can use Pascal's principle when using the
hydraulic system or when your driving a car. Fluid exerts pressure on any
surface it touches, by changing fluid pressure at any spot in a closed container you transmit pressure through out the container. An example
would be if you squeezed a water bottle while the top is sealed, the water
has no where to go. What happens next? The water presses harder on the
inside surface of the water bottle and water pressure increases everywhere in the bottle.
Fun fact: Pascal's name is used for the unit of pressure
Bernoulli’s Principles
Section 4
Bernoulli’s principle states that the faster a fluid
moves the less pressure it exerts. This helps with
flying by allowing us to calculate air pressure.
Bernoulli’s principle also helps to find out why
smoke rises which is because of the heat of the
smoke which causes high air pressure which
causes it to rise above the cooler air below it.
Another thing that helps us fly is an airplane's
wing which is made to create lift. Lift is an upward force that lifts the plane causing it to fly.
Zach Cothran
Briar murray
Laughs
For
Days!
Helicopters don't fly
they just beat the air to
submission!
Forget wind, speed, lift,
and drag; it is money
that makes airplanes fly.