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Table of contents
Introduction……………………………………………………pg .1
Web of Ideas…………………………………………………..pg .2
Abstract ……………………………………………………… pg .3
Body Report …………………………………………………...pg .4
Conclusion……………………………………………………..pg .8
Bibliography…………………………………………...............pg. 9
Introduction
A Force is a push or pull that gives energy to an object sometimes
causing it to start moving stop, or change direction. Pressure is a force that
acts over a certain area. Buoyancy is the phenomenon caused by the upward
force of fluid pressure. Forces, which do not act uniformly on all parts of a
body, will also cause mechanical stresses. In out project we will try to explain
& demonstrate how an egg can be completely sucked into a small bottle &
how little amount of force can make something 10 times its weight.
WEB OF IDEAS
1
Force is a push or pull
Force gives an object to move .stop moving or change direction
They are many kinds of forces such as electromagnetic forces. Nuclear
forces, elastic forces and friction.
Fluid in motion
The faster a fluid moves the less pressure it exerts.
FORCES
Sliding
Rolling
Fluid
The buoyant force on an object in an equal to the weight of the fluid displaced
by the objected this relationship in called Archimedes principle
FRICTION
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Abstract
A force is a push or a pull. Force gives an object the energy to move,
stop moving, or change direction. We will never be able to move without
exerting forces on things. Friction is a force that opposes motion. Without
friction, an object would continue to move at a constant speed forever. The
different forms of friction are sliding, rolling, and fluid.
FORCES & MOTION
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As we mentioned a force is a push or pull. Forces go way back to the
1600´s. 1687 to be exact. That was the year Sir Isaac Newton sought to
describe the motion of all objects using the concepts of Inertia and Force.
Doing so Newton established three laws of motion that till this very moment
are the way forces are described in physics. In brief, Newton’s first law states
that objects continue to move in a state of constant velocity unless acted upon
by an external net force or resultant force. Newton’s second law asserts the
proportionality of acceleration and mass to force. The third law is a result of
applying symmetry to situations where forces can be attributed to presence of
different objects.
There are many types of forces like; normal force, friction, tension,
elastic force, electromagnetic forces, gravity, nuclear force, among many
others.
Forces are often described as pushes or pulls as we mentioned before.
They can be due to the phenomena such as gravity, magnetism, or anything
else that might cause mass to accelerate. Did you know… that the concept of
force was essential to the development of mechanics and all of physics! Yes,
it’s true! Imagine without force, gravity wouldn’t exist, and we would all just
be floating in the air. To be able to understand better about the relationship
with force and gravity we’ll have to define the concept.
The natural phenomenon where objects with mass attract each other is
called gravitation or gravity. Gravity is responsible for keeping the Earth and
other planets in orbit around the sun. It is also responsible for keeping the
moon in orbit around the Earth. Have you ever heard the phrase “What goes
up, must come down”? Well this phrase is a great example or
gravity. Because of gravity, an object that is close to Earth falls toward the
surface of the planet. If an object that is already on the surface experiences a
downward force due to gravity. This experience is the force on our bodies as
our weight.
Another force is Electromagnetic force. Electromagnetic force is the
force that in, which an electromagnetic field exerts on electrically charged
particles. Electromagnetic force is what holds electrons and protons together
in atoms, and hold atoms together in order to make molecules. Originally,
electricity and magnetism were thought of as two separate forces. The
electromagnetic force is one of the four fundamental forces. The other
fundamental forces are: the strong nuclear force, the weak nuclear force, and
the gravitational
force. The electromagnetic
force
is responsible
for
basically all of the things a person encounters in daily life, besides
from gravity. In other words, all the forces involved in interactions
involving atoms can be tied to the electromagnetic force acting on
the electrically charged protons and electrons inside the atoms.
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The nuclear force is the force between two or more nucleons. It is
responsible for the attachment of protons and neutrons into the atomic nuclei.
Sometimes the nuclear force is called the residual strong force, in contrast to
the strong
interactions which
are
now
understood
to
arise
from quantum chromo dynamics or (QCD). Since nucleons have no color
charge, the nuclear force does not directly involve the force carriers of
quantum chromo dynamics, the gluons.
Another type of force in physics is Tension. This type of force is the
magnitude of the pulling force exerted by a string, cable, chain, or similar
object on another. It is also the opposite of compression. Since tension is a
type of force, it is measured in Newton’s (N). It is always measured parallel to
the string on which it applies. There are two main possibilities for systems of
objects held by strings. One of them is acceleration is zero and the system is
therefore in equilibrium or there is acceleration and otherwise a net force is
present.
Friction is the force resisting the relative lateral motion of solid
surfaces, fluid layers, or material elements in contact. Friction is not one of
the fundamental forces, since it is copied or derived from electromagnetic
force between
charged
particles,
including electrons, protons, atoms,
and molecules, concluding that it cannot be accepted as a first
principle. When contacting surfaces move parallel to each other, the friction
between the two surfaces converts into heat. Friction, if acting alone, will
cause a moving object to slow down and finally stop. There are three types of
friction. Rolling, sliding, and fluid friction. When solid objects slide over each
other, the type of friction that results is called sliding friction. The friction
produced by objects such as wheels or ball bearings is called rolling friction.
That is why most of the times wheels are often placed under objects that are
being moved. Sliding friction and rolling friction describe friction between two
solid surfaces, but friction also exists when an object moves across or through
a fluid. This type of friction is described as Fluid friction. Fluid friction occurs
when a fluid exerts the force. Friction is a very helpful force. Without friction
we wouldn’t be able to walk. When an object is placed in a fluid, the fluid
exerts an upward force. This upward force is known as buoyant force.
The buoyant force comes from the pressure applied on the object by
the fluid. Because the pressure and the depth both increases, the pressure on
the bottom of an object will always be larger than the force on the top. No
matter whether an object sinks or floats, there is always a buoyant force
present. Buoyancy is the upward force, caused by fluid pressure that keeps
things afloat. The net upward buoyancy force is equal to the magnitude of the
weight of fluid displaced by the body. This force enables the object to float or
at least seem lighter. The buoyant force on an object is equal to the weight of
the fluid displaced by the object. The relationship that is between buoyancy
and weight is called Archimedes´ principle. Depending on the size of the
buoyant force, we can determine what will happen to an object placed in
a fluid. In other words if the object will sink or stay afloat.
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When an object floats it is because it displaces a volume of fluid whose
weight is greater than or equal to its own weight. Even though, we ask
ourselves why do objects even float? The reason is because of the physical
property called density. Density is the ratio of the mass of a substance to its
volume. So to speak, density is mass divided by volume (D=M/V). Now that
we know what density is, the condition for floating can be stated in terms of
density. An object will float in a fluid if the density of that object is less than
the density of the fluid.
Pressure is caused by force. The forces that exist in fluids are caused
by the mass and motion of the particles making up the fluid. The “push”, or
force, particles exert over a certain area is called pressure. Fluid pressure is
exerted equally in all directions. There are many differences in pressure.
Fluids will often move from areas of higher pressure to areas of lower
pressure. The transmission of pressure equally in all directions in a liquid is
the principle behind hydraulic devices. Hydraulic devices produce enormous
forces with application of only a very small force.
Conclusion
6
Before reading on this subject we didn’t knew how great of importance
it is to have forces. In this project we discovered that there are many types of
forces, without this forces we wouldn’t be able to do everyday things like
walking, or even being alive
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Bibliography
http://en.wikipedia.org/wiki/Force
http://www-istp.gsfc.nasa.gov/stargaze/Snewton.htm
http://www.sambal.co.uk/forces.html
http://hyperphysics.phy-astr.gsu.edu/hbase/HFrame.html
http://dictionary.reference.com/browse/force+
http://thesaurus.reference.com/
http://physics.bu.edu/~duffy/semester1/c23_buoyant.htmlphysics
Exploring Physical Science
TASKS
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Clariza:
Roberta Porras:
Ana Cecilia Cueva:
Ana Paulina T:
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