Learn on PengiAmplify Science (California) Grade 8Chapter 3: Designing an Energy Solution

Lesson 5: End-of-Unit Assessment

Key Idea.

Section 1

Tracing Energy Transformation in Systems

Key Idea

Mastery of energy concepts allows for the analysis of complex devices, such as a wind-up radio. Analyzing such a device requires tracing the energy flow through specific components.

The sequence begins with kinetic energy from the human hand rotating a crank. This energy transfers to an internal coiled spring, where it is stored as elastic potential energy. When the radio is turned on, the spring uncoils, converting the potential energy back into kinetic energy to spin a generator. Finally, the generator converts this motion into electrical energy to power the speaker.

Lesson overview

Expand to review the lesson summary and core properties.

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Section 1

Tracing Energy Transformation in Systems

Key Idea

Mastery of energy concepts allows for the analysis of complex devices, such as a wind-up radio. Analyzing such a device requires tracing the energy flow through specific components.

The sequence begins with kinetic energy from the human hand rotating a crank. This energy transfers to an internal coiled spring, where it is stored as elastic potential energy. When the radio is turned on, the spring uncoils, converting the potential energy back into kinetic energy to spin a generator. Finally, the generator converts this motion into electrical energy to power the speaker.