Key term
CCEA AS-Level Physics 1210
Physical Quantities, Scalars and Vectors
Moments and Equilibrium
Linear Motion and Dynamics
Newton's Laws of Motion
Linear Momentum and Impulse
Work, Energy and Power
Current, Charge and Potential Difference
Resistance and Resistivity
Topic overviewResistance and Ohm's lawOhmic and non-ohmic behaviourResistors in series and in parallelInvestigating current, voltage and resistance in series and parallel circuitsElectrical power and energy in resistive circuitsResistivity and the equation R = ρl/AMeasuring the resistivity of a metalCurrent–voltage characteristics of a conductor, a lamp and a diodeResistance, temperature and superconductivity
Internal Resistance and Potential Dividers
Topic overviewInternal resistance and terminal potential differenceConsequences of internal resistance for external circuitsMeasuring electromotive force and internal resistanceThe potential divider and variable outputPotential dividers in lighting and heating control circuitsLoaded potential dividers and output voltage calculations
Waves
Refraction
Lenses
Superposition, Interference and Diffraction
Topic overviewSuperposition of wavesStanding waves, nodes and antinodesStanding waves on stretched stringsStanding waves in a pipe closed at one endMeasuring the speed of sound with a resonance tubeConditions for observable interferencePath difference and phase differenceYoung's double slitDiffraction at a single slitThe diffraction grating
Quantum Physics
Wave-Particle Duality
Astronomy
Practical Skills and Data Analysis
Topic overviewChoosing and using measuring instrumentsPrecision, accuracy and recording measurementsUsing the cathode ray oscilloscope to measure voltage and frequencyTables, graphs and presenting resultsLinearising a relationship and using the gradientAbsolute and percentage uncertaintyCombining uncertainties and uncertainty on a graphRandom and systematic error, reliability and refining an experiment
Work, Energy and Power
- 7 subtopics
- 21 things to know
- Unit AS 1
What Work, Energy and Power covers
Work, Energy and Power is examined in Unit AS 1, Forces, Energy and Electricity, and drawn on again in Unit AS 3, Practical Techniques and Data Analysis. It covers work done and energy transfer, calculating work done, including forces at an angle, gravitational potential energy, kinetic energy, conservation of energy and energy exchanges, work done by a resultant force and change in kinetic energy and power, efficiency and energy use in society.
Where it is assessed
Unit AS 1
Forces, Energy and Electricity, and again in Unit AS 3, Practical Techniques and Data Analysis.
Check the CCEA specification ↗The 7 subtopics
Each one has its own page. CCEA AS Physics students sit this topic in the first year.
- Work done and energy transferWork done by a force, one joule of work and what happens to energy whenever work is done.Open →
- Calculating work done, including forces at an angleRecall questions on W = Fs cos θ and why the cosine appears, the work done by a force at 90° and at 180° to the motion, the two ways of reading the equation, worked problems on a sledge, a lawnmower and a dragged crate, and why the force must be constant.Open →
- Gravitational potential energyGravitational potential energy and sign of Δp.Open →
- Kinetic energyRecall questions on the definition and the equation, the factor of four when speed doubles and what that means for braking distance, whether kinetic energy is a scalar, showing that the units reduce to the joule, why it can never be negative, and worked calculations on a car, a golf ball, a bullet and a cyclist.Open →
- Conservation of energy and energy exchangesRecall questions on the statement of the principle, the energy equation for a falling body and the derivation of v = √(2gΔh), how air resistance changes the exchange, why ramp shape does not matter, using light gates to investigate the exchange, and where the energy goes when a ball bounces low.Open →
- Work done by a resultant force and change in kinetic energyRecall questions on the equation ½mv² − ½mu² = Fs in words and in symbols, its derivation from suvat and the second law, when it may be applied, what a negative Fs means, and worked problems on an accelerating car, braking, an arrow and a bullet brought to rest.Open →
- Power, efficiency and energy use in societyPower and state the equation used to calculate it, watt and express it in SI base units and efficiency and explain why it has no unit.Open →
What you need to know
Answer each one before you reveal it.
Your recallNot started
Key term
State the equation for the work done by a constant force that is not along the line of motion, and define every symbol.
Key term
State the equation for the change in gravitational potential energy near the Earth's surface and define every symbol.
Numbers
A climber of mass 65 kg ascends a vertical height of 850 m. Calculate the gain in gravitational potential energy.
Key term
Why can g be quoted either as 9.81 m s⁻² or as 9.81 N kg⁻¹?
Key term
Explain why the kinetic energy of an object can never be negative.
Numbers
A stone is dropped from rest from a height of 20 m. Calculate its speed just before it lands, ignoring air resistance.
Numbers
A pendulum bob is released from a position 0.25 m above its lowest point. Calculate its speed at the lowest point, ignoring resistive forces.
Key term
Describe how light gates can be used to investigate the exchange between gravitational potential energy and kinetic energy for a falling body.
Key term
State the equation relating the work done by a constant resultant force to the change in kinetic energy, and define every symbol.
Numbers
A 900 kg car travelling at 30 m s⁻¹ is brought to rest by a constant braking force of 6.0 kN. Calculate the braking distance.
Key term
Why must F in ½mv² − ½mu² = Fs be the resultant force rather than just the applied force?
Key term
Define power and state the equation used to calculate it.
Key term
Show how the equation P = Fv follows from the definition of power.
Numbers
A crane lifts a 400 kg load through 12 m in 15 s. Calculate the useful output power.
Key term
Define the work done by a force.
Key term
Why does the factor cos θ appear in the equation for work done by a force acting at an angle to the motion?
Key term
Define kinetic energy.
Key term
State the SI unit of work and express it in SI base units.
Key term
What is the work done by a force that acts at 90° to the direction of motion?
Key term
State the equation for kinetic energy and define every symbol.
Take Work, Energy and Power further
The same content, four other ways.
Questions from this topic
Each one with the model answer underneath.
- 1
Define the work done by a force.
Model answer
The work done by a force is the product of the force and the distance moved in the direction of the force, W = Fs, where W is the work done in joules, F the force in newtons and s the distance moved in the direction of the force in metres.
- 2
State the SI unit of work and express it in SI base units.
Model answer
Work is measured in joules, and 1 J = 1 N m = 1 kg m² s⁻².
- 3
What does one joule of work mean in terms of a force and a distance?
Model answer
One joule is the work done when a force of 1 N moves its point of application a distance of 1 m in the direction of the force.
- 4
Is work done a scalar or a vector quantity?
Model answer
Work done is a scalar quantity, so it has magnitude but no direction, although it can be positive or negative depending on whether the force acts with or against the motion.
- 5
Explain what happens to energy whenever work is done.
Model answer
Whenever work is done, energy is transferred from one form or store to another, and the quantity of energy transferred is equal to the work done.
- 6
A crane lifts a steel girder steadily from the ground to the top of a building. Describe the energy transfers taking place.
Model answer
Electrical energy supplied to the motor is transferred mainly to the gravitational potential energy of the girder, with some transferred to the internal energy of the motor and cable through resistance and friction.
What is inside Levo
Six ways to work the same material.
Work, Energy and Power revision questions
- Is Work, Energy and Power examined at AS in CCEA Physics?
- Yes. It sits in Unit AS 1, which you take in the first year, so it is on the AS paper as well as counting towards the full A level.
- What does Work, Energy and Power cover in CCEA AS-Level Physics?
- 7 subtopics: work done and energy transfer, calculating work done, including forces at an angle, gravitational potential energy, kinetic energy, conservation of energy and energy exchanges, work done by a resultant force and change in kinetic energy and power, efficiency and energy use in society. Each one has its own page with questions and model answers.
- How is Work, Energy and Power organised?
- By the CCEA 1210 specification, subtopic by subtopic, so it matches the order you are taught it in.
Every question in Work, Energy and Power, on a schedule.
Attempt a question from memory, write the correct version, then attempt it again. Levo records the jump between your first attempt and your last, and brings each question back on the day you are due to forget it.
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