Heat engine efficiency
A heat engine in a heat-engine design review absorbs \(780\,\text{J}\) and produces \(270\,\text{J}\) of work. Calculate its efficiency as a percentage. Use the diagram first, then calculate the requested value. Enter the numerical result and choose the interpretation that matches the physics meaning.
Worked practice: physics data and result
Read the physical quantities first, then calculate the result and state what it means.
Write a full answer
Now write the response in full, in your own words — this is what the exam asks for. The AI marks it on the same moves you built above (focus, evidence, technique, judgement) and gives feedback on reasoning, evidence, and expression.