Transcript FORCE_AND_MOTION - Effingham County Schools

FORCE AND MOTION
Georgia Performance Standards
S4P3: Students will demonstrate the relationship
between the application of a force and the
resulting change in position and motion on an
object.
a. Identify simple machines
b. Using different size objects, observe how force affects
speed and motion.
c. Explain what happens to the speed or direction of an
object when a greater force than the initial one is
applied.
d. Demonstrate the effect of a gravitational force on the
motion of an object.
ESSENTIAL QUESTIONS
• How can force be used to make objects
move, change direction, or stop?
• How is the motion of an object related to
the size of the object and the amount of
force that is applied to the object?
• What is gravity and how does it affect
things on the earth?
• How do simple machines make work
easier for people?
• The motion of an object can be describes
by its speed and direction. Speed and
direction together determine an objects
velocity.
POSITION
• Position is an objects location.
• How would you describe your location?
• What would happen to your position if you
moved?
MOTION
• Motion is the change in an objects location
as compared to the object around it.
• If you move, your location changes when
you compare it to the objects around you.
• An object can appear to be moving when
compared to certain objects but not to others.
• Think about when you and a friend are riding in
a car. Compared to each other and the car, you
and your friend not moving. However, when you
are compared to objects outside the car, you
and your friend are moving.
• Even when you are standing still, the Earth
is still moving.
SPEED
• Speed is a measure of the distance an
object travels in a certain amount of time.
• You can find the speed of an object if you
know the distance the object traveled and
how long it took to travel that distance.
• Divide the distance by the time to find the
SPEED.
SPEED
• If a car travels 100 miles in 2 hours, its
SPEED is 50 miles per hour (MPH).
• 100 (the amount of miles) divided by 2 (the
time) equals 50.
• This gives you the speed of the car.
EVERY MOTION HAS A SPEED
• Some objects move very slowly.
• Some objects move very quickly.
• Glaciers move so slowly that they only
move downhill a few meters in a year.
• The wings of a hummingbird move up and
down so fast that they are just a blur.
DIRECTION
• Each motion has a direction as well as a
speed.
• DIRECTION tells you which way an object
is moving.
• You can describe direction using words
such as EAST, WEST, NORTH, SOUTH,
RIGHT, LEFT, UP, or DOWN.
VELOCITY
• Speed and direction together determine
the VELOCITY.
• Velocity is the measure of speed in a
certain direction.
FORCES OF MOTION
• A force is a push or a pull.
• A push is a force that moves objects
AWAY.
• A pull is a force that moves an object
closer.
FORCE
• A force can change the motion of an
object.
• A force can start an object moving, change
the direction or speed of the object, or stop
the object from moving.
• To change the speed or direction of an
object, you must change the force.
FRICTION
• The force that stops some objects from moving
when you stop pushing them is called
FRICTION.
• FRICTION is a force that slows or stops motion
between two surfaces that are touching.
• Friction exists between any two forces that are
touching. There is more friction between things
that are rough and there is between things that
are smooth.
FRICTION
• FRICTION can be useful. Without friction,
we would slip and slide on every surface.
• Without friction, your pencil would slide
between your fingers and you would not
be able to write.
GRAVITY
• GRAVITY is a force that pulls objects towards
each other.
• Earth’s gravity is what pulls skydivers towards
the ground when they jump out of an airplane.
• Gravity is what keeps your book on your desk
and makes the rain fall from the clouds.
SIMPLE MACHINES
• SIMPLE MACHINES help people do work
by changing a force. A machine is any tool
that makes work easier.
• Types of simple machines are an
INCLINED PLANE, WEDGE, SCREW,
LEVER, WHEEL AND AXLE, and a
PULLEY.
INCLINED PLANE
• An inclined plane is a simple machine
made up of a slanted surface.
• Ramps are examples of inclined planes.
• Inclined planes make it easier
to raise an object.
WEDGE
• Is a simple machine made up of two
inclined planes. It is V-shaped. It changes
a downward force to an outward force.
• This simple machine helps to cut or split
apart objects.
SCREW
• This is a simple machine made up of an
inclined plane wrapped around a column.
• It changes a weak circular force to a
strong downward force.
LEVER
• This is a simple machine that is made up
of a stiff bar that moves freely around a
fixed point.
• Examples of levers are see-saws and canopeners.
WHEEL and AXLE
• This is a simple machine made up of two
cylinders that turn on the same axis.
• The outer cylinder is called the wheel. The inner
cylinder, which is smaller, is called the axle.
• Examples of wheels and axles are car steering
wheels and doorknobs.
PULLEY
• This machine is made up of a rope fitted
around the rim of a fixed wheel.
• Pulleys are used to raise and lower
elevators, to move clothes lines back and
forth, and to lift a flag up a flagpole.
COMPOUND MACHINES
• Many of the things that you use every day
are made of two or more simple machines.
• A compound machine is when two or more
simple machines are put together to help
you do work.
COMPOUND MACHINE
• Scissors are made of two levers with a
fulcrum in the middle, The cutting blades
of the scissors are wedges.
COMPOUND MACHINE
A bicycle uses many simple machines. The
pedals are levers that supply force to the
sprocket. The sprocket is a wheel and axle
that uses gears to move the chain.
ESSENTIAL QUESTIONS
• How can force be used to make objects
move, change direction, or stop?
• How is the motion of an object related to
the size of the object and the amount of
force that is applied to the object?
• What is gravity and how does it affect
things on the earth?
• How do simple machines make work
easier for people?