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2 (a) Which statement describes conservation of energy in a closed system? A when there are energy transfers, the total energy reduces B when there are energy transfers, the total energy does not change C when there are no energy transfers, the total energy reduces D when there are no energy transfers, the total energy increases (b) A student uses the apparatus in Figure 3 to find out which of two materials, sand or sawdust, is the better insulator - Edexcel - GCSE Physics - Question 2 - 2022 - Paper 1
Question 2
2 (a) Which statement describes conservation of energy in a closed system? A when there are energy transfers, the total energy reduces B when there are en... show full transcript
Worked Solution & Example Answer:2 (a) Which statement describes conservation of energy in a closed system? A when there are energy transfers, the total energy reduces B when there are energy transfers, the total energy does not change C when there are no energy transfers, the total energy reduces D when there are no energy transfers, the total energy increases (b) A student uses the apparatus in Figure 3 to find out which of two materials, sand or sawdust, is the better insulator - Edexcel - GCSE Physics - Question 2 - 2022 - Paper 1
Step 1
Which statement describes conservation of energy in a closed system?
Answer
The correct answer is B: when there are energy transfers, the total energy does not change. This is because, according to the law of conservation of energy, energy may change from one form to another, but the total energy within a closed system remains constant.
Step 2
Draw a labelled diagram to show how the student should set up the equipment to investigate which material is the better insulator.
Answer
The diagram should include:
- A large copper can filled with hot water.
- A small copper can, which acts as an insulator.
- The insulator material being tested, sand or sawdust, placed between the two cans.
- A thermometer placed in the water to measure the temperature.
Ensure that the arrangement clearly shows the interaction between the cans and the insulator material.
Step 3
Step 4
Using the graph in Figure 4, describe how the thermal conductivity of expanded polystyrene changes with the density of expanded polystyrene.
Answer
From the graph, it can be seen that the thermal conductivity of expanded polystyrene decreases as the density increases. This implies that lower density expanded polystyrene has higher thermal conductivity, making it a better insulator, while higher density expanded polystyrene exhibits lower thermal conductivity.