Physics 4XPH1 — specification explorer

1. Units

• 1.1use the following units: kilogram (kg), metre (m), metre/second (m/s), metre/second2 (m/s2), newton (N), second (s) and newton/kilogram (N/kg)Unit 1
• 1.2Puse the following units: newton metre (Nm), kilogram metre/second (k g m /s)Unit 1

2. Movement and position

• 1.3plot and explain distance−time graphsUnit 1
• 1.4know and use the relationship between average speed, distance moved and time taken: average speed = distance moved time takenUnit 1
• 1.5practical: investigate the motion of everyday objects such as toy cars or tennis ballsUnit 1
• 1.6know and use the relationship between acceleration, change in velocity and time taken: acceleration = change in velocity time taken ( v − u ) a = tUnit 1
• 1.7plot and explain velocity−time graphsUnit 1
• 1.8determine acceleration from the gradient of a velocity−time graphUnit 1
• 1.9determine the distance travelled from the area between a velocity−time graph and the time axisUnit 1
• 1.10use the relationship between final speed, initial speed, acceleration and distance moved: ( final speed ) 2 = ( initial speed ) 2 + ( 2 acceleration distance moved × × ) v 2 = u 2 + ( 2 × a × s )Unit 1

3. Forces, movement, shape and momentum

• 1.11describe the effects of forces between bodies such as changes in speed, shape or directionUnit 1
• 1.12identify different types of force such as gravitational or electrostaticUnit 1
• 1.13understand how vector quantities differ from scalar quantitiesUnit 1
• 1.14understand that force is a vector quantityUnit 1
• 1.15calculate the resultant force of forces that act along a lineUnit 1
• 1.16know that friction is a force that opposes motionUnit 1
• 1.17know and use the relationship between unbalanced force, mass and acceleration: force = mass × acceleration F = m × aUnit 1
• 1.18know and use the relationship between weight, mass and gravitational field strength: weight = mass × gravitational field strength W = m × gUnit 1
• 1.19know that the stopping distance of a vehicle is made up of the sum of the thinking distance and the braking distanceUnit 1
• 1.20describe the factors affecting vehicle stopping distance, including speed, mass, road condition and reaction timeUnit 1
• 1.21describe the forces acting on falling objects (and explain why falling objects reach a terminal velocity)Unit 1
• 1.22practical: investigate how extension varies with applied force for helical springs, metal wires and rubber bandsUnit 1
• 1.23know that the initial linear region of a force-extension graph is associated with Hooke’s lawUnit 1
• 1.24describe elastic behaviour as the ability of a material to recover its original shape after the forces causing deformation have been removedUnit 1
• 1.25Pknow and use the relationship between momentum, mass and velocity: momentum = mass × velocity p = m × vUnit 1
• 1.26Puse the idea of momentum to explain safety featuresUnit 1
• 1.27Puse the conservation of momentum to calculate the mass, velocity or momentum of objectsUnit 1
• 1.28Puse the relationship between force, change in momentum and time taken: force = change in momentum time taken ( mv − mu ) F = tUnit 1
• 1.29Pdemonstrate an understanding of Newton’s third lawUnit 1
• 1.30Pknow and use the relationship between the moment of a force and its perpendicular distance from the pivot: moment = force × perpendicular distance from the pivotUnit 1
• 1.31Pknow that the weight of a body acts through its centre of gravityUnit 1
• 1.32Puse the principle of moments for a simple system of parallel forces acting in one planeUnit 1
• 1.33Punderstand how the upward forces on a light beam, supported at its ends, vary with the position of a heavy object placed on the beamUnit 1

1. Units

• 2.1use the following units: ampere (A), coulomb (C), joule (J), ohm (Ω), second (s), volt (V) and watt (W)Unit 1

2. Mains electricity

• 2.2understand how the use of insulation, double insulation, earthing, fuses and circuit breakers protects the device or user in a range of domestic appliancesUnit 1
• 2.3understand why a current in a resistor results in the electrical transfer of energy and an increase in temperature, and how this can be used in a variety of domestic contextsUnit 1
• 2.4know and use the relationship between power, current and voltage: power = current × voltage P = I × V and apply the relationship to the selection of appropriate fusesUnit 1
• 2.5use the relationship between energy transferred, current, voltage and time: energy transferred = current × voltage × time E = I × V × tUnit 1
• 2.6know the difference between mains electricity being alternating current (a.c.) and direct current (d.c.) being supplied by a cell or batteryUnit 1

3. Energy and voltage in circuits

• 2.7explain why a series or parallel circuit is more appropriate for particular applications, including domestic lightingUnit 1
• 2.8understand how the current in a series circuit depends on the applied voltage and the number and nature of other componentsUnit 1
• 2.9describe how current varies with voltage in wires, resistors, metal filament lamps and diodes, and how to investigate this experimentallyUnit 1
• 2.10describe the qualitative effect of changing resistance on the current in a circuitUnit 1
• 2.11describe the qualitative variation of resistance of light-dependent resistors (LDRs) with illumination and thermistors with temperatureUnit 1
• 2.12know that lamps and LEDs can be used to indicate the presence of a current in a circuitUnit 1
• 2.13know and use the relationship between voltage, current and resistance: voltage = current × resistance V = I × RUnit 1
• 2.14know that current is the rate of flow of chargeUnit 1
• 2.15know and use the relationship between charge, current and time: charge = current × time Q = I × tUnit 1
• 2.16know that electric current in solid metallic conductors is a flow of negatively charged electronsUnit 1
• 2.17understand why current is conserved at a junction in a circuitUnit 1
• 2.18know that the voltage across two components connected in parallel is the sameUnit 1
• 2.19calculate the currents, voltages and resistances of two resistive components connected in a series circuitUnit 1
• 2.20

  know that:

  • voltage is the energy transferred per unit charge passed
  • the volt is a joule per coulomb
  Unit 1
• 2.21know and use the relationship between energy transferred, charge and voltage: energy transferred = charge × voltage E = Q × VUnit 1

4. Electric charge

• 2.22Pidentify common materials that are electrical conductors or insulators, including metals and plasticsUnit 1
• 2.23Ppractical: investigate how insulating materials can be charged by frictionUnit 1
• 2.24Pexplain how positive and negative electrostatic charges are produced on materials by the loss and gain of electronsUnit 1
• 2.25Pknow that there are forces of attraction between unlike charges and forces of repulsion between like chargesUnit 1
• 2.26Pexplain electrostatic phenomena in terms of the movement of electronsUnit 1
• 2.27Pexplain the potential dangers of electrostatic charges, e.g. when fuelling aircraft and tankersUnit 1
• 2.28Pexplain some uses of electrostatic charges, e.g. in photocopiers and inkjet printersUnit 1

1. Units

• 3.1use the following units: kilogram (kg), joule (J), metre (m), metre/second (m/s), metre/second2 (m/s2), newton (N), second (s) and watt (W)Unit 1

2. Energy transfers

• 3.2

  describe energy transfers involving energy stores:

  • energy stores: chemical, kinetic, gravitational, elastic, thermal, magnetic, electrostatic, nuclear
  • energy transfers: mechanically, electrically, by heating, by radiation (light and sound)
  Unit 1
• 3.3use the principle of conservation of energyUnit 1
• 3.4know and use the relationship between efficiency, useful energy output and total energy output: useful energy output efficiency = × 100% total energy outputUnit 1
• 3.5describe a variety of everyday and scientific devices and situations, explaining the transfer of the input energy in terms of the above relationship, including their representation by Sankey diagramsUnit 1
• 3.6describe how thermal energy transfer may take place by conduction, convection and radiationUnit 1
• 3.7explain the role of convection in everyday phenomenaUnit 1
• 3.8explain how emission and absorption of radiation are related to surface and temperatureUnit 1
• 3.9practical: investigate thermal energy transfer by conduction, convection and radiationUnit 1
• 3.10explain ways of reducing unwanted energy transfer, such as insulationUnit 1

3. Work and power

• 3.11know and use the relationship between work done, force and distance moved in the direction of the force: work done = force × distance moved W = F × dUnit 1
• 3.12know that work done is equal to energy transferredUnit 1
• 3.13know and use the relationship between gravitational potential energy, mass, gravitational field strength and height: gravitational potential energy = mass × gravitational field strength × height GPE = m × g × hUnit 1
• 3.14know and use the relationship: 1 2 kinetic energy = 2 × mass × speed KE = 1 × m × v 2 2Unit 1
• 3.15understand how conservation of energy produces a link between gravitational potential energy, kinetic energy and workUnit 1
• 3.16describe power as the rate of transfer of energy or the rate of doing workUnit 1
• 3.17use the relationship between power, work done (energy transferred) and time taken: power = time taken work done W P = tUnit 1

4. Energy resources and electricity generation

• 3.18P

  describe the energy transfers involved in generating electricity using:

  • wind
  • water
  • geothermal resources
  • solar heating systems
  • solar cells
  • fossil fuels
  • nuclear power
  Unit 1
• 3.19Pdescribe the advantages and disadvantages of methods of large-scale electricity production from various renewable and non-renewable resourcesUnit 1

1. Units

• 4.1use the following units: degree Celsius (°C), Kelvin (K), joule (J), kilogram (kg), kilogram/metre3 (kg/m3), metre (m), metre2 (m2), metre3 (m3), metre/second (m/s), metre/second2 (m/s2), newton (N) and pascal (Pa)Unit 1
• 4.2Puse the following unit: joules/kilogram degree Celsius (J/k g ° C)Unit 1

2. Density and pressure

• 4.3know and use the relationship between density, mass and volume: density = volume mass m ρ = VUnit 1
• 4.4practical: investigate density using direct measurements of mass and volumeUnit 1
• 4.5know and use the relationship between pressure, force and area : pressure = area force F p = AUnit 1
• 4.6understand how the pressure at a point in a gas or liquid at rest acts equally in all directionsUnit 1
• 4.7know and use the relationship for pressure difference: pressure difference = height × density × gravitational field strength p = h × ρ × gUnit 1

3. Change of state

• 4.8Pexplain why heating a system will change the energy stored within the system and raise its temperature or produce changes of stateUnit 1
• 4.9Pdescribe the changes that occur when a solid melts to form a liquid, and when a liquid evaporates or boils to form a gasUnit 1
• 4.10Pdescribe the arrangement and motion of particles in solids, liquids and gasesUnit 1
• 4.11Ppractical: obtain a temperature–time graph to show the constant temperature during a change of stateUnit 1
• 4.12Pknow that specific heat capacity is the energy required to change the temperature of an object by one degree Celsius per kilogram of mass (J/kg °C)Unit 1
• 4.13Puse the equation: change in thermal energy = mass × specific heat capacity × change in temperature Δ Q = m × c × ΔTUnit 1
• 4.14Ppractical: investigate the specific heat capacity of materials including water and some solidsUnit 1