Energy and Its Forms

1
Energy and Its Forms

• Chapter 15 Section1
• Page 446-452

2
Class Agenda

• Starter Write the objectives for today (Complete
  an anticipation guide about Kinetic and Potential
  Energy)
• Read the Roller Coaster Activity (10 minutes)
• Discuss what happened in the activity
• Have the students read about Kinetic and
  Potential Energy
• Discuss Kinetic and Potential Energy (Takes notes
  on the board.
• Complete the Anticipation Guide for homework

3
Student Objectives 8.30.07 (pg. 8)

• The students will be able to explain the
  difference between potential and kinetic energy.
• The students will be able calculate the kinetic
  energy of a moving object.

4
Roller Coaster Lab

• Create an experimental design chart in your
  journal on page 6.
• Name the page Roller Coaster Lab. The hill of a
  roller coaster is called a summit.
• Use the foam tubing to make a roller coaster with
  three summits of equal heights, approximately 8
  cm off of the ground or table top.
• Did the marble make it all the way through the
  roller coaster?
• How could you change the roller coaster to make
  the marble move through the roller coaster?
• Try your idea. What happened? Record the data.
  (Will you be recording qualitative or
  quantitative data?)
• Graph your data.

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The Roller Coaster Activity

• You should have noticed that the first summit had
  to be greater than all of the other summits for
  the roller coaster to make it through the entire
  roller coaster.
• What happened when the first summit was smaller?
• Why didnt the roller coaster make it over?
• So, what is kinetic energy?
• Why didnt the roller coaster have enough kinetic
  energy?

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Two Types of Energy Notes

• Energy is the ability to do work.
• Energy and work are closely related because
  without energy, work cannot be done.
• Work is typically done on an object.
• When this work is done, the energy is transferred
  from one object to another. For example when
  Tiger Woods strikes a golf ball, hes doing work
  on the golf ball, hence he is transferring energy
  to the golf ball. How do we know this?
• The golf ball is moving.

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Kinetic Energy

• Kinetic Energy is the energy of motion. It is the
  energy that a moving object is carrying with it,
  while it is moving.
• The kinetic energy of moving object depends on
  its mass and speed. If a moving object has more
  mass, it will have more energy moving with it. If
  an object has more speed, it will have more
  energy moving with it.
• So, we can say that the kinetic energy of an
  object in motion is directly related to its
  speed and its mass.

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Two Major Types of Energy
9
Homework Kinetic Energy

• If the kinetic energy of a moving object can be
  found by the following equation, KE ½ mv2 ,
  find the KE of the moving object in the chart
  above.
• So, what happens when the KE of the moving object
  doubles?
• Is there a direct relationship between the mass
  of the object and its speed? Explain your
  answer.
• Graph the data presented in the chart. (Bar or
  Line Graph)

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Potential Energy--Continued
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Class Agenda 9.4.07

• Starter Complete the Before section on the
  anticipation guide for Potential Energy
• Read about Potential Energy
• Complete the After section of the anticipation
  guide for Potential Energy
• Math Connection How do we find the potential
  energy of an object.
• Graphing the data

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Student Objectives 8.30.07 (pg. 8)

• The students will be able to explain the
  difference between potential and kinetic energy.
• The students will be able calculate the kinetic
  energy of a moving object.

13
Objectives 9.4.07

• The students will be able to explain the
  difference between potential and kinetic energy.
• The students will be able to calculate the
  potential energy of an object standing still.
• The students will able to calculate the
  gravitational potential energy of an object
  falling.
• The students will be able to determine which type
  of graph is appropriate for graphing data related
  to kinetic and potential energy.

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Potential Energy

• Potential energy is stored energy. When the
  marble sat at the top of the summit, its energy
  was being stored. Since the marble didnt move,
  its energy didnt move either.
• When the marble moved, its potential energy was
  converted into kinetic energy.
• There are two types of potential energy.
• Gravitational Potential Energy energy that an
  object has based on how far it is from the
  ground. If an object position or altitude
  increases with respect to the ground, the
  objects potential energy increases. So, the
  potential energy of an object is directly related
  to its mass.
• Elastic Potential Energy energy that an object
  has based on how far it is stretched. The elastic
  potential energy of an object is directly related
  to how far the object is stretched. If you
  stretch a rubber band 10 cm, then it will go
  further than if you stretched it 3 cm.
• Elastic potential energy can be stored in objects
  that can be stretched or compressed

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Potential Energy

• So, how much energy did the marble have before it
  began to move. Well, youd have to use some math
  skills to figure this out.
• The Gravitational Potential Energy of an
  objective can be found by using the following
  equation, PE (m)(g)(h)
• In the chart on the next page, find the potential
  energy of an object that is not moving.

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Finding Potential Energy

• If the kinetic energy of a moving object can be
  found by the following equation, KE ½ mv2 ,
  find the KE of the moving object in the chart
  above.
• So, what happens when the KE of the moving object
  doubles?
• Graph the data presented in the chart. You must
  determine which type of graph to construct. (Bar
  or Line Graph)

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