Cambridge iGCSE 0654 (Physics Units) TOPIC P1. Motion P2. Matter and forces P3. Energy, work and power I can ……. Calculate average speed from s = d ÷ t Plot distance/time graphs and speed/time graphs Calculate speed from distanc/time graphs and acceleration from speed/time graphs Recognise what the following looks like on graphs: • An object at rest, • An object moving with constant speed, • An object moving with changing speed. State the difference between speed and velocity Calculate the area under a speed/time graph to work out distance covered Recognise motion that has a constant acceleration and nonconstant. Be able to calculate when constant Understand the difference between mass and weight. Recall Earth’s gravitational field (10m/s2) Know that mass is a property that “resists” change in motion. Know that weight is a concept due to the effect of a gravitational field on mass. Describe an experiment to find the density of objects using: Density = mass/volume Find the density of irregularly shaped objects using displacement theory Give the units of force as Newtons Describe how forces can change an object’s: • Size • Shape • motion Hookes Law Interpret extension-load graphs Recall and use the expression: Force = constant x extension (F=kX) Recall and use the relationship between force and acceleration (F=ma) Recognise the term “limit of proportionality” in extensionload graphs Understand about resultant forces Pressure • Relate pressure to force and area. • Use the equation P= F/a) Recall the units of energy (Joules) Identify examples of energy in different forms: Gravitational – thermal – chemical – strain – nuclear – electrical – kinetic - light - sound Apply the concept of energy conservation in examples of energy transfer Discuss in depth how an object may have energy due to it’s motion (kinetic) or it’s position (gravitational) P3. Energy, work and power continued…. P4. Simple kinetic molecular model of matter P5. Matter and thermal properties Use the expressions KE = ½mv2 and GPE = mxgxh Distinguish between renewable and non-renewable energy sources. Describe the sun as the source of all energy sources apart from geothermal and nuclear. Describe how the following methods are used to obtain useful energy 1. Fuels (chemical stores) 2. Water (waves, tides and hydroelectric dams) 3. Geothermal 4. Nuclear fission (nuclear power) 5. Heat and light from the sun (solar etc) 6. Wind Give advantages and disadvantages for the above. Appreciate and calculate energy efficiency Efficiency = useful/input x 100 Work done Calculate work done from force and distance (WD=fxd) Power Calculate power from work done and time (Power =WD ÷ t) Describe the difference between solids, liquids and gases. Say which particles have a higher temperature by their motion. Describe pressure in terms of a molecules’ motion Say what would happen to the pressure of a gas if the temperature was changed (at constant volume) Relate the properties of solids/liquids/gases to the forces and distances between molecules and the motion. Pressure: Relate the change in volume of a gas to the change in pressure (at a constant temperature) p x V = constant (at room temperature) Describe evaporation Explain how evaporation causes cooling (linking to energy) Discuss how evaporation is effected by • temperature, • surface area and • air flow. Explain the idea of expansion caused by heating (contraction by cooling) Identify and explain how thermal expansion can be useful and consequential Link temperature and volume to pressure Understand the term thermal capactiy Describe an experiment to find the specific heat capacity (SHC) of a substance Recall and use: energy = mass x SHC x change in temp Discuss the difference between boiling and evaporation State that boiling and melting involve energy input, but no change in temperature Use the terms latent heat of vaporization and latent heat of fusion. Conduction: Explain this heat transfer (in solids), and P6. Transfer of thermal energy P7. Waves P8. Light P9. Electromagnetic spectrum describe experiments to find the properties of good/bad heat conductors Convection: Explain this heat transfer (in fluids) Relate this energy transfer to density changes. Radiation: Understand that infra-red is the region of the EMS involved in heat transfer by radiation. Know that radiation does not need a medium to travel. Describe experiments to show the properties of good and bad emitters of heat (absorbers too!) Appreciate and discuss the consequences and uses of conduction, convection and radiation Recall and use the equation: Wave speed = frequency x wavelength Understand that waves transfer energy without transferring matter Use the terms: • wave speed • frequency • wavelength • amplitude Understand the difference between longitudinal and transverse waves (and give examples) Understand about wave reflection and direction-change. Reflection Use the law of angle of incidence=angle of reflection Perform simple constructions based on reflections in mirrors Identify total internal reflection and describe its presence in optical fibres (uses in medicines and ICT) Refraction Describe the movement of light through a material of changing density State the meaning of the term critical angle Dispersion Describe the dispersion of light by a glass prism. Lens Use ray diagrams to show light moving through a converging lens Use the terms: • focal length • principle focus Draw simple ray diagrams that show real and virtual images being made State the approximate speed of waves in the EMS Describe the features of the EMS (Order, wavelength etc) Describe the roles of the EMS waves in: 1. radio & television 2. Satellite TV and telephones 3. Romote controles, electricals and intruder alarms 4. Medicine and security Appreciate the safety precautions needed with regards to xrays P10. Sound P11. Magnetism P12. Electricity Recall that sound production is due to vibrations State the range of frequencies humans can hear at Show understanding that a medium (particles) are needed for sound travel Communicate a possible experiment for finding the approximate speed of sound Relate frequency and amplitude to pitch and loudness Explain how an echo is formed Describe the transfer of sound in air in terms of compressions and rarefractions. Describe the properties of magnets Identify the pattern of field lines around a bar magnet Distinguish between iron and steel magnetic properties Appreciate the difference between permanent magnets and electromagnets Explain how magnetism can be induced. Understand the use of: current, pd, emf, resistance, charge. Understand how electrostatic charges are formed Understand what potential difference does in a circuit. Use the relationship I = Q/t Know the difference between conventional current and real current Understand resistance, use R = V/I and relate to wire characteristics (length and diameter/cross sectional area) Appreciate the hazards of: damaged cables, overheating and damp conditions Show understanding of how circuit breakers are used. P13. Electric circuits P14. Electromagnetic effects Draw and interpret diagrams containing: Switches – resistors – lamps – ammeters – voltmeters – fuses – magnetising coils – transformers – bells - relays Be able to construct series and parallel circuits Know in depth how the current, voltage and resistance changes throughout a series/parallel circuit. Describe the role of thermistors and light depending resistors Explain the action of a relay and show understanding of circuits with a light sensitive switch and temperature systems. Describe how an electromotive force (EMF) can be induced by a changing magnetic field State the factors that affect the size of an EMF. Describe a generator, the use of slip rings, and the voltage change produced by one over time Understand how a transformer works to transmit high voltage electricity in order to reduce energy losses. Explain the above energy loss reduction. Recall and use: Vp ÷ Vs = Np ÷ NS Explain patterns of a magnetic field due to currents in wires and in solenoids (coiled wires) Describe how changing the size and direction of the current will effect the magnetic field Describe the effect of a coil of wire in an electric field, and relate this turning effect to the action of a motor.