Pearson Edexcel · GCSE · Physics
Course version: 1PH0 · Version from Sept 2016
Explain that where there are energy transfers in a closed system there is…
Full specification wording
Topic 3 – Conservation of energy: 3.6 Explain that where there are energy transfers in a closed system there is no net change to the total energy in that system
A closed system is one in which no energy enters or leaves from outside.
Checked against the Pearson Edexcel 1PH0 specification (opens in a new tab) on .
- Point 5 of 10
Study notes
From the checked teaching notes for this specification point.
The idea
A closed system is one in which no energy enters or leaves from outside. Within it, energy may move between stores — for example a falling ball transfers energy from its gravitational potential store to its kinetic store, and friction may then transfer some to the thermal store of the ball and surroundings. The key idea is that the total energy stays the same: the energy gained by one store equals the energy lost by another, so the net change across the whole system is zero. Learners should be able to explain this, not just state it, by tracking each transfer and showing that gains and losses balance. A useful method is to list the stores before and after an event and check that the sum is unchanged.
What earns the marks
- States that a closed system is one in which no energy enters or leaves from outside.
- Explains that energy is transferred between stores within the system rather than being created or destroyed.
- Shows that the energy gained by one store equals the energy lost by another store.
- Concludes that the total energy of the closed system has no net change.
- Applies the idea to a named example, such as a falling ball transferring energy from gravitational potential to kinetic stores.
Common mistakes and how to put them right
Claims that energy is used up or disappears during a transfer.
Put it right by stating that energy is conserved and only moves between stores.
Treats an open system as closed.
Put it right: Check whether energy crosses the boundary before applying the no-net-change rule.
Adds the energy in each store without accounting for losses.
Put it right: Balance the gains against the losses to show the total is unchanged.
Exam tips
- Identify the system boundary first and state whether it is closed before explaining the transfers.
- Name each store involved and the direction of each transfer so the balance is explicit.
- Finish with a clear statement that the total energy shows no net change, since that is the point being explained.
Try the lesson
The start of the Topic 3 – Conservation of energy: 3.6 Explain that where there are energy transfers in a closed system there is no net change to the total energy in that system lesson, made from checked teaching notes for this specification point.
Have a go first
A ball is dropped inside a sealed, insulated box. As it falls and bounces, energy is transferred between gravitational, kinetic and thermal stores. What happens to the total energy inside the box?
There is more to this lesson
The full lesson goes on to check your understanding and help you earn the marks. Create a free account to carry on, with your progress saved.
A week of Premium from your first lesson · Then the free plan continues · No card, no charge
Test your understanding of Topic 3 – Conservation of energy: 3.6 Explain that where there are energy transfers in a closed system there is no net change to the total energy in that system
Active recall beats re-reading. Take an instant quiz now to test what you’ve learned and lock it into long-term memory.
A week of Premium from your first lesson · Then the free plan continues · No card, no charge