Conservation of Energy | Edexcel GCSE Combined Science Physics, Higher tier (1SC0)
Conservation of Energy
- 103 questions
- 7 subtopics
- Paper 5
- Paper 5
Conservation of Energy is examined in Paper 5, Physics 1.
It covers gravitational potential and kinetic energy, energy transfer diagrams and conservation of energy, energy stores and closed systems, dissipation and wasteful energy transfer, reducing unwanted energy transfer, efficiency and how to increase it and energy resources and trends in their use.
Sample questions from Conservation of Energy
Answer each one closed book first, then open the answer.
-
Gravitational potential and kinetic energy
Explain why only the vertical height, and not the distance travelled along a ramp, is used to calculate a change in gravitational potential energy.
Show the answer
Gravitational potential energy depends on how far the object is raised against gravity, which is the vertical height. -
Gravitational potential and kinetic energy
Calculate the kinetic energy of a 0.4 kg ball moving at 5 m/s.
Show the answer
KE = ½ × 0.4 × 5² = 5 J. -
Energy transfer diagrams and conservation of energy
State what the total width of all the output arrows of a Sankey diagram must equal.
Show the answer
It must equal the width of the input arrow, because energy is conserved. -
Energy transfer diagrams and conservation of energy
A student says that a car's energy is used up when the car brakes. Explain why this statement is wrong.
Show the answer
The energy is not used up but transferred to the thermal stores of the brakes and the surroundings. -
Energy stores and closed systems
Explain why a hammer head becomes warm after it has repeatedly struck a nail.
Show the answer
Each impact transfers energy from the kinetic store of the hammer to the thermal stores of the hammer, the nail and the wood. -
Energy stores and closed systems
What is meant by a closed system in the study of energy?
Show the answer
A closed system is one that no energy enters or leaves, so energy is only transferred between stores inside it. -
Dissipation and wasteful energy transfer
Explain why rubbing your hands together makes them feel warm.
Show the answer
Work done against friction transfers energy to the thermal store of the skin, raising its temperature. -
Dissipation and wasteful energy transfer
Describe the wasteful transfer that takes place in a loudspeaker.
Show the answer
Some of the energy supplied heats the coil instead of being transferred as sound.
The 7 subtopics
One subtopic is one session. Work down the list.
| Subtopic | What it covers | Questions |
|---|---|---|
| Gravitational potential and kinetic energy | Change in gravitational potential energy = mass × gravitational field strength × change in vertical height, finding energy, height and mass, why only vertical height counts, kinetic energy = ½ × mass × (speed)², and speed after a fall. | 14 |
| Energy transfer diagrams and conservation of energy | What energy transfer and Sankey diagrams show, arrow widths and why outputs equal the input, diagrams for a torch and a hairdryer, the principle of conservation of energy, and why energy is wasted but never used up. | 12 |
| Energy stores and closed systems | Energy store changes for a thrown ball, a freewheeling cyclist, a crashing car, a hammer, a kettle and a braking car, then what a closed system is and why its total energy stays fixed. | 15 |
| Dissipation and wasteful energy transfer | Why friction makes mechanical processes wasteful, warming on slides and rubbed hands, why dissipated energy is hard to recover while the total is conserved, and dissipation in lamps, loudspeakers, mobile phones and bicycles. | 12 |
| Reducing unwanted energy transfer | Reducing unwanted energy transfer with wall and loft insulation, double glazing, lubrication and draught-proofing, how wall thickness and thermal conductivity affect a building's rate of cooling, and cavity walls filled with foam. | 12 |
| Efficiency and how to increase it | The efficiency equation, why efficiency has no unit, calculating efficiency, useful energy, energy supplied and energy wasted, and increasing efficiency by lubrication, streamlining, LED lamps and insulated pipes, though never to 100%. | 14 |
| Energy resources and trends in their use | Fossil fuels, nuclear fuel, bio-fuel, wind, hydro-electricity, tides and solar energy, renewable versus non-renewable resources, their reliability and environmental effects, trends in energy use, ethical issues and the limits of science, and charting resources. | 24 |
How the guide is worked
Answering a question from memory stores it far better than reading the answer again. The guide runs that as a fixed procedure on one subtopic at a time, about twenty minutes a session.
-
Step 1 · Closed book
Cover the answers. Work through one subtopic and write down what you can. Leave blanks where you have nothing.
-
Step 2 · Open book
Go back to the top. Read each printed answer and write it out in full, including the ones you had right.
-
Step 3 · Closed book again
Same questions, same order, from memory. The gap between pass one and pass three is the session result.
Read the full method, the return schedule and the research behind it.
Nearby topics
Edexcel GCSE Combined Science Physics, Higher tier Active Recall Guide
Every topic, not just this one. 1,449 questions with their answers.