FORCE AND MOTION

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FORCE AND MOTION

• What do you know about force and motion?

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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.
• Identify simple machines
• Using different size objects, observe how force
  affects speed and motion.
• Explain what happens to the speed or direction of
  an object when a greater force than the initial
  one is applied.
• Demonstrate the effect of a gravitational force
  on the motion of an object.

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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?

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Motion

• The motion of an object can be described by its
  speed and direction. Speed and direction together
  determine an objects velocity.

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POSITION

• Position is an objects location.
• How would you describe your location?
• What would happen to your position if you moved?

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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.

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Motion

• 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 are not moving. However, when you are
  compared to objects outside the car, you and your
  friend are moving.

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Earth is Moving

• Even when you are standing still, the Earth is
  still moving.

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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.

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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.

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EVERY MOTION HAS A SPEED

• Some objects move very slowly.
• Some objects move very quickly.

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Speed

• Glaciers move so slowly that they only move
  downhill a few meters in a year.

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Speed

• The wings of a hummingbird move up and down so
  fast that they are just a blur.

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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.

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VELOCITY

• Speed and direction together determine the
  VELOCITY.
• Velocity is the measure of speed in a certain
  direction.

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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.

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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.

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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.

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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.

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GRAVITY

• GRAVITY is a force that pulls objects towards
  each other.
• Earths 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.

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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.

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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.

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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.

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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.

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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 can-openers.

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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.

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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.

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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.

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COMPOUND MACHINE

• Scissors are made of two levers with a fulcrum in
  the middle, The cutting blades of the scissors
  are wedges.

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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.

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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?

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