Energy, Forces, and Motion A Science Module for Grades 3-5 Excellence in K-8 Science: A NC MSEN Statewide Initiative

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Energy, Forces, and MotionA Science Module for
Grades 3-5Excellence in K-8 Science A NC MSEN
Statewide Initiative

• Instructors
• Beth Brampton, New Hanover County Schools
• Dennis Kubasko, UNC Wilmington

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Organizing Topics

• In the early grades of science education it is
  imperative to provide an experiential approach to
  energy, forces, and motion. It is important to
  develop accompanying vocabulary as it becomes
  relevant to the students through their
  experiences. A more in-depth theoretical
  understanding of energy, forces, and motion need
  not be undertaken until middle school.

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Relevant context

• Relevant Content in the National Standards
  Document
• Relevant Goals and Objectives from the North
  Carolina Standard Course of Study
• Integration across the curriculum
• Module Overview of Science Background for
  Instructors
• Energy, Forces Motion Dictionary

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Learning Cycle 1

• Investigating Force and Motion
• Questions
• What is a Force?
• What is Motion?
• How are they related?

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Introduction

• These investigations use the concepts of force
  and motion to develop an initial understanding of
  energy basics.
• Through an observation of motion of some familiar
  toys, students will develop the vocabulary
  necessary to answer the following questions
• How does the toys motion change?
• What forces are acting on the toy?
• Where does the energy come from? Where does it
  go?

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Instructional Strategy

• Engage The Domino Theory, Thumper Activity
• Explore Energy Toys Learning Center
• Explain Cartoon
• Elaborate Motion Detectors
• Evaluate Roller Coaster
• Making Connections

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Science Background Information

• Observation of the motion of simple toys will
  expose students to the concepts of potential and
  kinetic energy, forces (such as gravity and
  friction), velocity, acceleration, inertia,
  Newtons Laws of Motion, and conservation of
  energy.

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1st Law or the Principal of Inertia

• If an object is left alone, not disturbed, it
  continues to move with constant velocity in a
  straight line (if it was originally moving) or it
  continues to stand still (if it was just standing
  still).

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Engage

• The two kinds of energy are stored energy
  (Potential) and moving energy (Kinetic).
• The classic domino rally stores up energy or
  gains potential energy as the dominos are set up.
  As they fall they have moving or kinetic energy.

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Engage

• Thumper is a model for the magic trick where the
  table cloth is pulled off the table while leaving
  the dishes on the table.
• If the table cloth is pulled off rapidly, the
  dishes remain in place (inertia) because the
  force (a push or pull) is not transferred from
  the table cloth to the dishes.
• If the table cloth is pulled out slowly, then
  friction will transfer the force to the dishes
  and all will fall off the table.

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Explain

• In groups of 2-4 teachers explore the motion of
  the group of toys. Please be encouraged to try
  out all of the toys. Each group should analyze
  the motions of the toys.
• How did you start the toys to move? What was the
  push or pull?
• What did the toy do? Did it roll, bounce, slide,
  etc.?
• What happened just before the toy stopped moving?
• What do you think makes the toy stop?

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Explore

• Tops -- The principle of rotational inertia
  states that a spinning object will continue to
  spin unless acted upon by an outside torque
  (circular force).
• A spinning top on a level surface spins around
  its axis and does not fall.
• Spinning the top produces rotational inertia
  (amount of spin and the direction of spin) which
  keeps it in place as it rotates.
• The forces which cause it to stop rotating, and
  therefore fall, are friction (between the table
  and top) and air resistance.

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Explore

• Rattlebacks have a counterclockwise spin bias
  that results from the shape of the smooth
  ellipsoidal bottom and the distribution of the
  mass with respect to the axis of spin. The long
  axis of the ellipsoid is aligned at an angle of 5
  to 10 degrees to the long axis of the flat top.
  Just prior to reversing direction, a Rattleback
  rocks up and down on its long axis, hence the
  name.

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Explore

• Topsy-Turvy or Mushroom Tops will invert if there
  is sufficient angular inertia. If the top is
  spun fast enough the stem of the top will touch
  the surface of the table. If the stem touches,
  slides across the surface and the top is still
  moving fast enough, the friction can enable the
  top to flip and continue to spin on the stem.

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Explore

• Spring-Ups Energy is stored as elastic
  potential energy in the toy's spring when the
  energy of your muscles pushes down on the toy
  (compressing the spring) and makes the suction
  cup stick. When the suction cup lets loose, the
  elastic potential energy in the spring is
  converted to kinetic energy. The toy has the
  most kinetic energy when the spring is completely
  expanded. As the toy jumps, the kinetic energy is
  being changed into gravitational potential
  energy.

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Explain

• Spring-ups often have a flipping motion because
  the spring bends slightly as the suction cup
  releases. As a result, the force exerted is not
  perfectly vertical.
• At its highest point, almost all of the toy's
  kinetic energy is converted into gravitational
  potential energy. As the toy comes back down,
  the gravitational potential energy is converted
  back to kinetic energy. When the toy hits the
  table and stops, it loses both its potential and
  kinetic energy. Where does the energy go?
  Primarily, it becomes heat (energy), but some of
  it goes into sound (energy).

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Explain

• Wind-up toys -- The energy is supplied by human
  muscles winding the spring. This energy is
  stored in the spring as elastic potential energy
  and is stored there until you release the winder.
  Then the potential energy is converted to the
  kinetic energy of the toy's movement. The toy
  moves, and its internal parts also move. Both of
  these movements involve kinetic energy.
• This toy has the most potential energy when you
  have finished winding the winder and haven't yet
  released it. The toy has the most kinetic energy
  when it is moving fastest ----- somewhere in the
  middle of the motion.
• The force of friction between the tires and the
  floor causes the toy to slow down and eventually
  stop. The friction of the moving internal parts
  of the toy also contributes to the slowing and
  stopping of the toy. The toy's kinetic energy is
  turned into heat (energy) - the toy and the floor
  each get a little warmer.

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Explain

• Balls -- A ball held at some distance above the
  ground possesses gravitational potential energy
  from the force needed to lift the object against
  gravity (force). When it is released, it falls
  and gains kinetic energy and loses potential
  energy.
• When the ball collides with the floor, some of
  this kinetic energy is stored as elastic
  potential energy in the ball and the floor. The
  particles in the ball and the floor squeeze
  together like tiny springs. How well the
  material in the ball springs back to its original
  shape after being deformed determines the height
  of the rebound.
• If the material absorbs the potential energy and
  returns to its original shape slowly or not at
  all, much of the energy is not returned to the
  motion of the ball, resulting in a low bounce.
  The collision is said to be inelastic.

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Evaluate

• Make a roller coaster that will have the
  following elements hill, turn and loop. State a
  time limit, work in groups. The expectation is
  that they will explain the order of the elements,
  energy input and output, problems encountered,
  and how well were expectations met.

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Making Connections

• A real life connection would be automobile
  accidents. Forces, motion and energy transfer
  have very graphic results. The type of car
  (mass), and the speed of the vehicle will
  determine the forces applied. The condition of
  the road, if it is icy, wet, sand, etc., would
  bring friction into the discussion.