Forces and Motion

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Forces and Motion

• PART 1

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Ping Pong Poppers

• Materials
• 1 popper
• Hard surface
• Ping pong ball
• Hard rubber ball
• Goggles
• Flip the disc inside out and set it on a hard
  surface. WATCH.
• WHAT HAPPENED?

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Ping Pong Poppers

• Now flip the disc inside out again and quickly
  put a ping pong ball in the popper.
• WHAT HAPPENED?
• Repeat again with a rubber ball.
• WHAT HAPPENED?

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Review

• the ability to do work or work being done on an
  object.
• Radiant
• Sound
• Thermal
• Chemical
• Mechanical
• Electrical

• Energy
• Forms of energy

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POTENTIAL ENERGY

• energy of position
• stored energy.
• Examples
• Stretched rubber band
• Stacked dominos
• Charged battery

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KINETIC ENERGY

• energy of motion
• Examples
• A flying rubber band
• falling dominos

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Video clip examples

• Rubber band airplane http//gtm-media.discoveryed
  ucation.com/videos/10184/sec9730_256k.asf
• Ski jump http//gtm-media.discoveryeducation.com/
  videos/10184/sec9731_256k.asf
• Roller Coaster http//gtm-media.discoveryeducatio
  n.com/videos/10184/sec9733_256k.asf

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Properties of Kinetic Energy

• The more mass an object has the greater the
  kinetic energy.
• If 2 objects have the same mass, the faster
  object has more kinetic energy.
• Car going 25 kph vs. car going 50 kph

vs.
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LAW OF CONSERVATION OF ENERGY

• Energy cannot be created nor destroyed but may be
  changed from one form to another.

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Quiz A. Energy B. kinetic C. Potential

• The ability to do work or work being done on an
  object is
• Energy of position or stored energy
• Can depend on height
• A flying rubber band
• A rubber band stretched or stacked dominos
• energy of motion
• Based on movement

A. Energy
C. Potential
C. Potential
B. Kinetic
C. Potential
B. Kinetic
B. Kinetic
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Motion

• Motion is the change in position of an object
  compared to the position of some other object.

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Reference Point

• Reference point is something used to determine if
  another object is moving.

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Reference Point
Figure 1
Figure 2

• Describe the cars motion from figure one to
  figure 2.

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Reference Point
Figure 1
Figure 2

• Describe the cars motion from figure one to
  figure 2.

What is the reference point? How did you use it
to describe the motion of the car?
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Changes in Motion

• The motion of objects change when
• the object is speeding up.
• the object is slowing down.
• the object changes direction.
• Unbalanced forces act on an object.

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Forces

• A Force is a push or a pull.
• Examples include
• Gravity
• Contact force
• Friction
• Magnetic force
• Electrical force

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Balanced or Unbalanced

• Forces can be

Which side will win?????
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Video Clips

• Play Push and Pull clip 314
• (You may need to log into United Streaming)

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Balanced Forces

• do not change the objects motion

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Unbalanced Forces cause objects to

• Start moving
• Stop moving
• Change direction

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Unbalanced Forces

• When in the opposite direction, the box moves the
  direction the larger force is pushing.

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Quiz

• A push or pull is called a ______
• When two equal forces are acting on an object in
  opposite directions they are _________ forces
• When forces are unequal they are _________
  forces.
• Forces are described in strength and ________

• Force
• Direction
• Balanced
• Unbalanced

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Frayer Models
On pages 64 and 65. Complete for homework
Potential Energy
Kinetic Energy