Investigating Kinetic and Potential Energy

In this lesson, students use a variety of resources to explore the concepts of potential, kinetic, and total energy within different types of systems. Students watch a video that explains the transfer of energy in a trebuchet's release, use an interactive activity to determine the types of energy involved in different parts of a roller coaster ride, do an in-class investigation that demonstrates the effect of mass and gravity on energy systems, explore the difference between gravitational and elastic potential energy, and finally, use the formulas for kinetic and potential energy to examine the path of a projectile. This lesson provides the media resources and teacher materials necessary to walk students through the process of understanding the difference between kinetic and potential energy.

Standards & Objectives

Learning objectives: 
  • Understand the difference between kinetic and potential energy
  • Identify the types of potential energy in a system
  • Identify the areas in a system where potential and kinetic energy exist
  • Apply the formulas for kinetic and potential energy to determine the amount of energy in a system

Lesson Variations

Blooms taxonomy level: 
Understanding
Extension suggestions: 
  • Direct students to the Projectile Motion Flash Interactive. This activity allowsstudents to change variables — such as mass and speed of a projectile, and angle of launch — while attempting to hit a target. In addition,the measuring tool allows them to determine the highest point the projectile has reached, and this height can be used to calculate the GPE ofthe object.
  • After students have had an opportunity to explore the interactive activity, ask these questions:
    • Where is the PE greatest? Smallest?
    • Where is the KE greatest? Smallest?
    • What happens to the PE as the KE increases?
    • What difference do the mass and shape of the projectile make in the absence of air resistance?
    • Compare the horizontal distance the object travels during the first and second seconds. Can you find evidence that thehorizontal velocity changes over time? What about the vertical velocity?
    • Have students drop objects other than golf balls from varying heights onto different materials and measure the relativeamount of GPE. Are the results similar to the golf ball data? Does the type of surface on which the object lands make a difference? Why?
  • Have students visit NOVA Medieval Siege for an interactive experience with the factors affecting how atrebuchet fires.
  • Have students design and build model trebuchets like the one seen in the video and test them using different-size masses ascounterweights. The GPE can be determined by measuring the height to which the counterweight is raised. Examples of materials that can beused to build the trebuchets include LEGO’s® and balsa wood. (Examples of LEGO® trebuchets are available online.)

Helpful Hints

Materials:

  • Ramps or chutes
  • Marbles

For each group of two students:

  • One golf ball
  • One meter stick
  • One balance
  • Teacher Notes PDF Document
  • What Is Energy? PDF Document
  • Kinetic and Potential Energy PDF Document
  • Energy in a Golf Ball Activity Data Sheet PDF Document
  • NOVA Medieval Siege

References

Contributors: