Click to go back to home page
Instructional Planning
The following is an example of planning an experiment that spans two days.

HOW DO DIFFERENT TYPES OF SLOPED HILLS AFFECT THE WORK DONE BY AN OBJECT
Developed by Tim Loper

Grade Level: Junior/Senior
Science Course: Physics
Time Frame: Two class periods consisting of 45 min.

Purpose: Students will investigate how different sloped hills will affect the work done by an object. They will hypothesize whether or not the different types of slopes will affect the object's speed. The slopes will all start and end at the same heights. They will also decide whether or not the work done will be affected and how will that work be related to the speed of the objects. For example, if a certain slope gives the greatest speed will that same slope give the greatest amount of work?

This laboratory experiment is part of an overall unit of energy conservation. The students will make connections with work and speed. They will also discover that as long as the object starts and ends at the same height, the speeds will be the same and therefore the work will be the same. This will introduce the work-energy theorem, as well as the conservation of energy. The class has covered work up to this point.

This unit addresses the Standard for Physical science (grades 9-12), which is concerned with energy conservation (NSES, p. 180), and forming a testable hypothesis along with properly testing and analyzing the results (NSES p. 175). The specific areas are:

  • Energy is transferred from one state to another.
  • Energy is always conserved.
  • Energy can be in the form of kinetic and potential.
  • Kinetic energy is the energy of motion.
  • Potential energy is the energy of position.

    Objectives: At the conclusion of the unit students will have the ability to:

    Concepts:
    1. Understand potential and kinetic energy.
    2. Understand how they relate in the conservation of energy law.
    3. Understand how the energy is transformed from one form to another.
    4. Understand some of the reasons for energy loss.

    Inquiry:
    1. Interpret their results of the experiment to decide how work and the initial heights relate.
    2. Make a connection between the speeds and the work done. They can follow up with this by     using a photo-gate timer to see the speeds to verify their analysis.


    Materials/Equipment:
    1. Multiple inclined plane apparatus
    2. Ruler
    3. Photo-gate timer
    4. Metal ball

    Instructional Activities:

    Day one:

    Engage/Explore
  • Introduce the experiment.
  • The students will hypothesize which hill will produce the most work and the greatest speed.
  • They will start the ball at the top of each hill and the ball will roll to the bottom and hit a cup     that is mounted on an eraser.
  • They will measure the distance the eraser is moved.
  • They will repeat this process for another ball with half the mass.


    Day two:

    Explanation/Elaboration
  • From their data, they will determine whether or not the slope of the hill affected the work     done for each ball.
  • They will decide based on their findings whether or not the speed is different for each hill or     the same.
  • They will verify by using the photo-gate.

    Assessment Plan:

    Assessment
  • The students will be required to do a lab report over their results.
  • The students will also take a quiz to test their understanding of energy conservation.