Grade 8 - Energy and Power

This sub-organizer contains the following sections:
Prescribed Learning Outcomes
Suggested Instructional Strategies
Suggested Assessment Strategies
Recommended Learning Resources

PRESCRIBED LEARNING OUTCOMES

It is expected that students will:

incorporate selected devices in the design of energy transmission and conversion systems
explain how systems transmit and convert energy
identify how simple machines are combined into energy and power systems
construct devices that are powered in various ways

To view the prescribed learning outcomes for Energy and Power in other grades click on an icon below.

SUGGESTED INSTRUCTIONAL STRATEGIES

Learning about energy conversion, transmission, and conservation helps students understand the impact of energy use on individuals, society, and the environment. To enhance their understandings of the relationship between energy and power, students design and build devices that use energy in various ways, and present their findings using various media.

Have students discuss and list power sources used in Canada in the 1800s. Have them compare the list to power sources used today.
Ask students to predict future sources of energy and power and their possible costs to the environment and society.
Lead a class discussion on the discrepancy between energy use per capita in Canada and in France, Mexico, or Nepal.
Have students in small groups use a variety of mechanical, electric, and solar devices (e.g., solar cells) to create products that demonstrate the conversion of energy (e.g., a mock car using mechanical energy from a mousetrap).
Ask students to use a suitable medium (e.g., Hypercard stacks, video) to explain and demonstrate how the systems they construct transmit and convert energy.
Have students dismantle discarded items and identify simple machines or tools (e.g., wheels, pulleys, levers). The parts could be used in other student projects.
Encourage students to work co-operatively to construct devices that combine simple machines (e.g., a time-delay mechanism). Discuss applications for the devices in the community.

SUGGESTED ASSESSMENT STRATEGIES

As students work on the design and construction of mechanical devices, they demonstrate their understandings of how energy is transmitted and converted, how simple machines are combined to create complex movements, and how energy can be conserved within a mechanical system.

Question

Conference with individual students to assess their understandings of how simple machines are used in the design of complex devices. Use prompts such as:
- What simple machines have you used in your design?
- How would a change in this simple machine affect the system as a whole?
- What other simple machine could you use in your design? What function would it serve?
- How would it change the system?

Collect

Examine design portfolio for evidence that students are able to:
- incorporate a variety of simple machines into their designs
- identify ways to conserve energy in their products
- modify a design to solve an energy transmission or conversion problem

Self-Assessment

Engage students in a design challenge that requires incorporating at least four simple machines in a device that converts energy and puts this energy to useful work (e.g., lifting, propelling, pulling). Have students brainstorm and refine a list of criteria to assess their designs. Criteria may include efficiency, usefulness, and innovation in design.