Year 7 Science · Unit 3 · Lesson 13
Challenge Worksheet
Learning Goals
Evaluate the claim
Someone claims...
"If we can't create or destroy energy — and the law of conservation of energy proves this — then there really is no energy crisis. We have the same total energy we've always had. The solution is simple: just transform what we already have more efficiently, and the problem goes away."
(a) What part of this claim is supported by the science you have learned? Reference the law of conservation of energy in your answer.
(b) What is misleading or incomplete about this claim? Think carefully about what happens to energy once it becomes heat or sound — can it easily be used again?
(c) What evidence or extra information would you need to determine whether improving efficiency alone could solve Australia's energy challenges?
1. A coal power station is 33% efficient. A solar farm is 22% efficient. A student argues that coal power is the better choice because it is more efficient. Write a response that agrees with the maths but challenges the conclusion, using at least two scientific ideas.
2. Australia's Snowy 2.0 project stores energy by pumping water uphill (using surplus electricity) then releasing it downhill to generate power later. Trace the full energy transformation chain for this process, starting from "electrical energy from a solar farm". Include at least four transformation steps and identify where energy is lost at each stage.
Wrap Up
In one sentence, what was the main idea of this lesson?