Year 9 Science · Unit 3 · Lesson 1
Challenge Worksheet
Learning Goals
What if…?
Scenario
Imagine that tomorrow, scientists announced that the law of conservation of energy no longer held. Energy could now be created from nothing, a battery could charge itself without any input, a car could run forever without fuel, and a solar panel could output more electricity than the sunlight falling on it. Australia's government immediately cancels all energy taxes and subsidies, because energy is now infinite and free.
Using what you know from this lesson, predict and explain what this scenario reveals about why the conservation of energy law matters. Consider the impact on the laws of physics, on energy economics, and on the environment. Use scientific terms in your answer.
1. Scientists have tested the law of conservation of energy millions of times and it has never been violated. Explain why this makes it a "law" rather than just a theory, and what it would mean for science if a single experiment disproved it.
2. Consider two energy sources: a coal-fired power station (chemical energy → electrical) and a solar panel (light energy → electrical). Both ultimately supply electrical energy. Evaluate which source better illustrates the idea that "energy transformation always involves some waste", using specific examples of where waste occurs in each.
Wrap Up
In one sentence, what was the main idea of this lesson?