Grade Level(s): 9, 10, 11, 12
Computer for Presenter, Basic Calculators, LCD Projector, Microsoft Office, Sensors/Probeware
Keywords: potential and kinetic energy, mechanical energy, energy
Lesson Plan Template: Predict-Observe-Explain
Learning Objectives: What should students know and be able to do as a result of this lesson?
Students will be able to:
- describe the relationship between the gravitational potential energy and kinetic energy of an object.
- predict when an object is at its maximum gravitational potential energy or maximum kinetic energy.
- apply formulas to calculate the gravitational potential energy and kinetic energy of an object.
Prior Knowledge: What prior knowledge should students have for this lesson?
Students should have a basic knowledge of motion (displacement, velocity, acceleration), mass, and how to measure height and calculate velocity.
Guiding Questions: What are the guiding questions for this lesson?
- What factors affect an object's gravitational potential energy?
- What factors affect an object's kinetic energy?
- Which positions will not require the students to have to pedal?
- Which student will have the greatest potential and kinetic energy?
- Which direction will give more potential energy to school or back to the hotel?
Teaching Phase: How will the teacher present the concept or skill to students?
The teacher will present the big idea question: "What is the relationship between a falling object's height and the object's maximum speed?" Students will complete a lab activity to answer the question. The teacher will demonstrate the setup of a ramp with an object (a marble, toy car, etc.) to roll down that ramp. The teacher will demonstrate how students will measure the distance and time of the object when it reaches the flat surface. (See the attached Height vs Speed Lab)
- Students will be asked to predict how increasing the height an object affects the speed.
- Students will use ramps, which can be made out of cardboard or siding and raise them at different heights. Students can develop their own heights as an inquiry activity.
- Students will record the time an object takes to travel a set distance from the base of the ramp.
- Students will then calculate the object's velocity on the flat surface. (velocity = distance/time)
- Students will repeat the activity for at least two additional ramp heights.
Guided Practice: What activities or exercises will the students complete with teacher guidance?
Given a scenario, the teacher will demonstrate how to calculate the potential energy and kinetic energy for two students as they bike to a math competition. (See the attached Bicycle Activity)
The teacher will demonstrate how to calculate potential energy, and from that determine the velocities and kinetic energy at the bottom of the hill.
Independent Practice: What activities or exercises will students complete to reinforce the concepts and skills developed in the lesson?
Students will complete the Height vs Speed Lab and share their data with the class.
In groups, students will calculate the kinetic, potential, and mechanical energy as well as the velocity for the two bicyclists in various positions during the Bicycle Activity.
Closure: How will the teacher assist students in organizing the knowledge gained in the lesson?
Students will complete a data table and bar graph with the observed heights and speeds and the heights, potential energy, and kinetic energy of the two bicyclists.
In the Bicycle Activity, students will:
- Complete questions and calculations for potential and kinetic energy.
- Complete bar graph of potential and kinetic energy.
Students will also complete a six-question summative assessment.
Students will predict how increasing the height of a falling object affects the speed of a falling object. The teacher will be able to use the predictions to gauge possible misconceptions and areas where understanding may be lacking.
Students will be able to self-assess their understanding during the observation stage of the lesson. Students will also complete the Height vs. Speed Lab (see attachments) that will assist the teacher in adjusting learning. Also, the teacher will be able to adjust teaching for the Bicycle Activity through questioning and discussion in the observation and explanation part of the lesson.
Feedback to Students
Students will measure heights and speeds of falling objects and see how their observations match their predictions.
The teacher will guide students through the calculation of kinetic and potential energy. Students will write the answers on the board or a MS Word or Excel document that students can view and compare.
Accommodations & Recommendations
Arrange students into heterogeneous groups of three.
Struggling students may need extra resources such as the PhET simulation "Energy Skate Park."
Students may need to be given gravitational potential energy, kinetic energy, and mechanical energy equations along with tables to input to label each variable so that the quantitative calculations are kept clear for each position.
Have students look up the elevations for the Tour de France and calculate the kinetic and potential energies for Bettina and Jacob if they rode their bikes down those mountains!
Students may also develop further knowledge of mechanical energy as well as the conservation of energy in systems other systems, such as thermal energy.
Suggested Technology: Computer for Presenter, Basic Calculators, LCD Projector, Microsoft Office, Sensors/Probeware
Special Materials Needed:
- Ramp material (cardboard, PVC pipe, etc.) as well as a base with variable height (ring stands, stacks of books, etc.)
- Masking tape
- Meter sticks
- Stop watch or photo gates
Links for tutorials from Physics Classroom for teachers and students needing more information on gravitational potential energy and kinetic energy:
Note: in the Bicycle Scenario, the gravitational potential energy is calculated using the Position 8 (at a height of 20 m) as the frame of reference. Therefore all gravitational potential energy calculations use a height subtracted from this 20 m. Calculations can be made using the full height at each position, but it will change the gravitational potential energy, mechanical energy, and subsequent kinetic energy calculations. It will not change the velocity calculations.
Source and Access Information
Name of Author/Source: Jeanne Murphy
District/Organization of Contributor(s): Duval
Access Privileges: Public
* Please note that examples of resources are not intended as complete curriculum.