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This PowerPoint resource provides an engaging and comprehensive lesson designed to teach students about efficient energy transfers, calculating efficiency, and understanding energy dissipation in everyday systems. It is ideal for high school physics classes focusing on energy concepts.

Key learning objectives:

• Defining efficiency as the proportion of energy transferred usefully in a process.
• Calculating efficiency using the equation: Efficiency= Useful Output Energy (or Power)/Total Input Energy (or Power)
• Rearranging the efficiency equation to calculate input, output, or wasted energy.
• Understanding why real-life systems can never achieve 100% efficiency due to energy dissipation.

Resource features:
The lesson begins with a starter activity to activate prior knowledge about energy units, forces, and the impact of friction on work done. Students are introduced to the concept of energy efficiency through relatable examples, such as lightbulbs, blenders, and mobile phones.

Key topics include:

• Differentiating between useful and wasted energy outputs.
• Analyzing energy transfers in common devices and identifying inefficiencies.
• Practical examples and scenarios, such as calculating the efficiency of a filament lightbulb or a blender.
• Using both energy and power values to calculate efficiency in a variety of contexts.

Interactive activities guide students through calculating efficiency as a decimal and percentage, rearranging formulas, and interpreting energy dissipation in systems. Students also explore why some devices are more efficient than others and how efficiency impacts energy conservation and cost savings.

Updated: April 2025

File details:
This editable ‘.pptx’ file aligns with physics curricula and is suitable for classroom instruction or independent study. It includes clear visuals, worked examples, and practice problems, making it an essential tool for mastering energy efficiency and conservation concepts.