Physics. Combined Science. Paper 2. Checklists and Knowledge Organisers

Transcription

1 Combined Science Physics Paper 2 Checklists and Knowledge Organisers Included in this booklet are the Personalised Learning Checklists (PLC s) for the biology topics included in paper 2. As you work through the topic and revise it at a later date, RAG rate your understanding of each statement to help you focus your revision. The knowledge organisers will support you in addressing these areas.

2 The following table lists the command words used in the external assessments. Command word Add/Label Requires the addition or labelling to a stimulus material given in the question, for example labelling a diagram or adding units to a table. Give careful consideration to all the factors or events that apply and identify which are the most important or relevant. Make a judgement on the importance of something, and come to a conclusion where needed. Obtain a numerical answer, showing relevant working. If the answer has a unit, this must be included. This can include using an equation to calculate a numerical answer. Requires the synthesis of a number of variables from data/information to form a judgement. Looking for the similarities or differences of two (or more) things. Should not require the drawing of a conclusion. Answer must relate to both (or all) things mentioned in the question. Looking for the similarities and differences of two (or more) things. Should not require the drawing of a conclusion. Answer must relate to both (or all) things mentioned in the question. Assess Calculate Comment on Compare Compare and contrast Complete Deduce Describe Determine Devise Discuss The answer must include at least one similarity and one difference. Requires the completion of a table/diagram. Draw/reach conclusion(s) from the information provided. To give an account of something. Statements in the response need to be developed as they are often linked but do not need to include a justification or reason. The answer must have an element which is quantitative from the stimulus provided, or must show how the answer can be reached quantitatively. To gain maximum marks there must be a quantitative element to the answer. Plan or invent a procedure from existing principles/ideas. Identify the issue/situation/problem/argument that is being assessed within the question. Explore all aspects of an issue/situation/problem/ argument. Draw Estimate Evaluate 14 Investigate the issue/situation etc. by reasoning or argument. Produce a diagram either using a ruler or using freehand. Find an approximate value, number, or quantity from a diagram/given data or through a calculation. Review information (e.g. data, methods) then bring it together to form a conclusion, drawing on evidence including strengths, weaknesses, alternative actions, relevant data or information. Come to a supported judgement of a subject s qualities and relation to its context. Command word Explain An explanation requires a justification/exemplification of a point. Give/State/Name Give a reason/reasons Identify Justify Measure Plot Predict Show that Sketch State and explain State what is meant by Write The answer must contain some element of reasoning/ justification, this can include mathematical explanations. All of these command words are really synonyms. They generally all require recall of one or more pieces of information. When a statement has been made and the requirement is only to give the reasons why. Usually requires some key information to be selected from a given stimulus/resource. Give evidence to support (either the statement given in the question or an earlier answer). To determine the dimensions or angle from a diagram using an instrument such as a ruler or protractor. Produce a graph by marking points accurately on a grid from data that is provided and then drawing a line of best fit through these points. A suitable scale and appropriately labelled axes must be included if these are not provided in the question. Give an expected result. Verify the statement given in the question. Produce a freehand drawing. For a graph this would need a line and labelled axis with important features indicated, the axis are not scaled. Make a point and link ideas to justify that point. An explanation requires a justification/exemplification of a point. The answer must contain some element of reasoning/justification, this can include mathematical explanations. When the meaning of a term is expected but there are different ways of how these can be described. When the questions ask for an equation. Occasionally we will ask candidates for a suggestion, for example when asking them to apply their knowledge to a novel situation, but the word suggest is not the command word. The command word follows the word suggest. In our analysis of our current papers, we have noticed that candidates struggle to interpret what is being asked in a suggest question, so we add a word which gives more clarity over what is required, e.g. suggest an explanation. Verbs preceding a command word Suggest a Always used with another command word, e.g. Suggest an explanation. 15

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4 Combined Science Physics Paper 2 Checklists Physics 6 - Work Done and Power TOPIC Student Checklist R A G Describe the changes involved in the way energy is stored when systems change Topic 8 Energy forces doing work Topic 9 Forces and their effects Draw and interpret diagrams to represent energy transfers Explain that where there are energy transfers in a closed system there is no net change to the total energy in that system Identify the different ways that the energy of a system can be changed through work done by forces, in electrical equipment and in heating Describe how to measure the work done by a force and recall that energy transferred (joule, J) is equal to work done (joule, J) Recall and use the equation: E = F d Describe and calculate the changes in energy involved when a system is changed by work done by forces Recall and use the equation to calculate the change in gravitational PE when an object is raised above the ground: ΔGPE = m g Δh Recall and use the equation to calculate the amounts of energy associated with a moving object: KE = ½ m v 2 Explain, using examples, how in all system changes energy is dissipated so that it is stored in less useful ways Explain that mechanical processes become wasteful when they cause a rise in temperature so dissipating energy in heating the surroundings Define power as the rate at which energy is transferred and use examples to explain this definition Recall and use the equation: P = E/t Recall what one Watt is equal to Recall and use the efficiency equation Describe, with examples, how objects can interact with and without contact Explain the difference between vector and scalar quantities using examples HT ONLY: Use vector diagrams to illustrate resolution of forces, a net force, and equilibrium situations HT ONLY: Draw and use free body force diagrams HT ONLY: Explain examples of the forces acting on an isolated solid object or a system where several forces lead to a resultant force Explain ways of reducing unwanted energy transfer through lubrication Physics 7 - Electricity Topic Student Checklist R A G Topic 10a Electricity and circuits (part a) Topic 10a Electricity and circuits (part a)+19:4925:4919:4925:49a225:32a225:32 Draw and use electric circuit diagrams Describe the differences between series and parallel circuits Recall how to measure potential difference using a voltmeter in series and parallel circuits Define potential difference end describe what a volt is Recall and use the equation: E = Q V

5 Recall how to measure current using an ammeter in series and parallel circuits Explain what electrical current is Topic 10b Electricity and circuits (part b) Recall and use the equation: Q = I t Describe that when a closed circuit includes a source of potential difference there will be a current in the circuit Recall that current is conserved at a junction in a circuit Describe how to use a variable resisitor in a circuit Recall and use the equation: V = I R Explain why, if two resistors are in series, the net resistance is increased, whereas with two in parallel the net resistance is decreased Calculate the currents, potential differences and resistances in series circuits Explain the design and construction of series circuits for testing and measuring Core Practical: Construct electrical circuits to: investigate the relationship between, V, I and R for a resistor and a filament lamp Explain how I varies with V for the following devices and how this relates to R for filament lamps, diodes and fixed resistors Describe how the resistance of a light-dependent resistor(ldr) varies with light intensity Describe how the resistance of a thermistor varies with change of temperature ( neg temp thermistors only) Explain how the design and use of circuits can be used to explore the variation of resistance in: filament lamps, diodes, thermistors & LDRs Recall that, when there is an electric current in a resistor, there is an energy transfer which heats the resistor Explain how electrical energy is dissipated when an electrical current does work against electrical resistance Explain the energy transfer when electrical energy is dissipated when an electrical current does work against electrical resistance Explain ways of reducing unwanted energy transfer through low resistance wires Describe the advantages and disadvantages of the heating effect of an electric current Use the equation: E = I V t Describe power as the energy transferred per second and recall that it is measured in watt Recall and use the equation: P = E/t Explain how the power transfer in any circuit device is related to the potential difference across it and the current in it Recall and use the equations: P = I V and P = I 2 R Describe how, in different domestic devices, energy is transferred from batteries and a.c. mains motors and heating devices Explain the difference between direct and alternating voltage Describe what direct current (d.c.) is and recall the objects that supply it Describe what alternating current (a.c.) is and recall the frequency and voltage in the UK Explain the difference in function between the live and the neutral mains input wires Explain the function of an earth wire and of fuses or circuit breakers in ensuring safety Explain why switches and fuses should be connected in the live wire of a domestic circuit Recall the potential differences between the live, neutral and earth mains wires Explain the dangers of providing any connection between the live wire and earth Describe, with examples, the relationship between the power ratings for domestic electrical appliances and the changes in energy when used

6 Physics 8 - Electromagnetism TOPIC Student Checklist R A G Topic 12 Magnetism and the motor effect Topic 13 Electromagnetic induction Describe the interactions between like and unlike magnetic poles Describe the uses of permanent and temporary magnetic materials including cobalt, steel, iron and nickel Explain the difference between permanent and induced magnets Describe the shape and direction of the magnetic field around bar magnets and for a uniform field Relate the strength of the magnetic field to the concentration of lines Describe the use of plotting compasses to show the shape and direction of the field of a magnet and the Earth s magnetic field Explain how the behaviour of a magnetic compass is related to evidence that the core of the Earth must be magnetic Describe how to show that a current can create a magnetic effect around a long straight conductor Describe the shape of the magnetic field produced and relating the direction of the magnetic field to the direction of the current Recall that the strength of the field depends on the size of the current and the distance from the long straight conductor Explain how inside a solenoid the fields from individual coils can add together or cancel HT ONLY: Recall what happens when a current carrying conductor is placed near a magnet experiences in terms of force HT ONLY: Explain how magnetic forces are due to interactions between magnetic fields HT ONLY: Recall and use Fleming s left-hand rule to represent the relative directions of the force HT ONLY: Use the equation: F = B I l HT ONLY: Explain how the force on a conductor in a magnetic field is used to cause rotation in electric motors Explain why, in the national grid, electrical energy is transferred at different voltages Explain where and why step-up and step-down transformers are used in the transmission of electricity in the national grid Use the power equation (for transformers with100% efficiency): V p I p =V s I s Physics 9 - Particle Model and Materials Topic Student Checklist R A G Topic 14 Particle model Use a simple kinetic theory model to explain the different states of matter Recall and use the equation: ρ = m/v Core Practical: Investigate the densities of solid and liquids Explain the differences in density between the different states of matter in terms of the arrangements of the particles Name and describe the physical changes of state Describe the differences between chemical and physical changes Explain how heating a system will change the energy stored within the system and affect temperature at the state of the material Define the terms specific heat capacity and specific latent heat and explain the differences between them

7 Use the equation: ΔQ = m c Δθ Use the equation: Q = m L Topic 15 Forces and matter Explain ways of reducing unwanted energy transfers through thermal insulation Core Practical: Investigate the properties of water by determining the specific heat capacity of water for melting ice Explain the pressure of a gas in terms of the motion of its particles Explain the effect of changing the temperature of a gas on the velocity of its particles and hence on the pressure Describe the term absolute zero, 273 C, in terms of movement of particles Convert between the kelvin and Celsius scales HT ONLY: Explain why doing work on a gas can increase its temperature, including a bicycle pump Explain, using springs and other elastic objects, that stretching, bending or compressing an object requires more than one force Describe the difference between elastic and inelastic distortion Recall and use the equation for linear elastic distortion including calculating the spring constant: F = k x x Use the equation to calculate the work done in stretching a spring: E = ½ k x x 2 Describe the difference between linear and non-linear relationships between force and extension Core Practical: Investigate the extension and work done when applying forces to a spring

8 CP7-8 Work and Power Links to previous units: Ways energy can be stored and transferred. Key Term Action reaction forces component (forces) contact forces electric field/ electrostatic field energy force field free body force diagram friction gravitational field magnet magnetic field Pairs of forces on interacting objects. Action reaction forces are always the same size, in opposite directions, and acting on different objects. They are not the same as balanced forces, which act on a single object. One of two forces at right angles to each other, resolved from a single force. Forces where there needs to be contact between objects before the force can have an effect (e.g. friction or upthrust). The space around an object with a charge of static electricity, where it can affect other objects. Something that is needed to make things happen or change. The space around something where a noncontact force affects things. Examples include magnetic fields and gravitational fields. A diagram of an object showing all the forces acting on it and the size and direction of those forces. A force between two surfaces that resists motion. The space around any object with mass where its gravity attracts other masses. An object that has its own magnetic field around it. The area around a magnet where it can affect magnetic materials. magnetic material A material such as iron that is attracted to a magnet. magnetism The force caused by magnets or magnetic materials. How can we change the energy in a system? How do we calculate work done and power? Effects of balanced and unbalanced forces. Representing forces in diagrams. Key Term The size of something, such as the size of a magnitude force or the measurement of a distance. net force Another term for resultant force. non-contact A force that can affect something from a distance (e.g. gravity). force normal contact A force that acts at right angles to a surface force as a reaction to a force on that surface. The amount (rate) of energy transferred per power second. The units are watts (W). resolving Representing a single force as two forces at (forces) right angles to each other. The total force that results from two or more forces acting upon a single object. It is found resultant force by adding together the forces, taking into account their directions. Another term for net force. A quantity that has a magnitude (size) but scalar quantity not a direction. Examples include mass, distance, energy and speed. A way of working out the resultant forces or component forces by drawing a diagram scale diagram where the lengths of arrows represent the sizes of the forces. static electricity Electric charges on insulating materials. A force that pushes things up in liquids and upthrust gases. vector vector diagram watts (W) work done A quantity that has both size and direction. A diagram on which vectors are displayed (e.g. a scale diagram, a free body force diagram). The unit for measuring power. 1 watt = 1 joule of energy transferred every second. A measure of the energy transferred when a force acts through a distance.

9 CP9 Electricity Did you know? An incubator has many circuits to keep a premature baby alive. It monitors the baby s temperature, blood, oxygen concentration, heart rate and breathing rate. What is current, charge and potential difference and how do we calculate them? It can make automatic adjustments to the baby s environment and alert staff to problems. Key Term atom electron neutron nucleus parallel circuit proton series circuit shell (electron shell) ampere (A) ammeter battery cell (physics) conserved potential difference voltage voltmeter volt (V) charge coulomb (C) rate ohm (Ω) resistance direct proportion The smallest neutral part of an element that can take part in chemical reactions. A tiny particle with a negative charge and negligible mass. A particle found in the nucleus of an atom, having zero charge and a mass of 1 (relative to a proton). The central part of an atom. A circuit in which there is more than one path for the current to follow. A particle found in the nucleus of an atom, having a positive charge and the same mass as a neutron. A type of circuit with only one loop of wire. A distinct region around a nucleus that can be occupied by electrons and is usually drawn as a circle. The unit for current. Can be shortened to amp. A meter used to measure current. More than one cell joined together. A chemical store of energy that can be transferred by electricity. Kept the same throughout. The energy transferred to or from a coulomb of electric charge when it flows between two points. Sometimes called voltage. See potential difference. Meter used to measure potential difference (or voltage). The unit for potential difference (or voltage). Electric charge is a basic property of matter that causes forces between charged particles or objects. It can be positive or negative. The charge on something is the sum of the charges of all the positively and negatively charged particles they contain. The unit for measuring charge. How quickly something happens. The unit for measuring electrical resistance. A measurement of how difficult it is for electricity to flow through something. A relationship in which when one variable is multiplied by any number the other variable is multiplied by the same number, e.g. doubling one variable doubles the other. A direct proportion is seen as a straight line through the origin when the two variables are plotted on a scatter graph. Do you know the components that can change their resistance? Key Term diode A component that lets electric current flow through it in one direction only. light-dependent A resistor whose resistance gets lower when light shines resistor (LDR) on it. light-emitting diode (LED) A diode that emits light when current flows through it. A component whose resistance changes as its temperature thermistor changes. The thermistors you will meet increase in resistance as the temperature increases. dissipated Spread out. Work is done when a force moves an object through a distance. work So work is done when a charged particle is moved between two points in an electric field. The unit for work is the joule (J). power The amount (rate) of energy transferred per second. The units are watts (W). power rating The energy transferred per second by an appliance. watt (W) The unit for measuring power. 1 watt = 1 joule of energy transferred every second. alternating current (a.c.) Current whose direction changes many times each second. direct current (d.c.) A current that flows in one direction only, such as the current produced by a battery. hertz The unit for frequency, 1 hertz is one wave per second. Electricity supplied from power stations using the national mains electricity grid. national grid The system of wires and transformers that distributes electricity around the country. thermal energy store circuit breaker earth wire fuse live wire neutral wire The hotter something is, the more energy it has in its thermal energy store. It is sometimes called heat. An electrical component that switches off the current in a circuit if there is a fault and the current rises to dangerous levels. It can be switched back on when the fault is fixed. A low-resistance path for electric current to flow to earth for safety if there is a fault in an appliance. A safety device containing a length of wire that is designed to melt if the current in a circuit gets too hot. The wire connected to the a.c. supply from the power station. The voltage oscillates between the maximum V in one direction and the maximum V in the opposite direction. A neutral wire is held at or near earth potential (0 V). It completes the circuit to the power station and carries current.

10 Key Term alternating current core electrical power electromagnet electromagnetic induction Fleming s left-hand rule induce induced magnet magnetic field magnetic flux density Current whose direction changes many times each second. The innermost part of something e.g. the central part of the Earth. Power transferred by electricity. A magnet made using a coil of wire with electricity flowing through it. A process that creates a current in a wire when the wire is moved relative to a magnetic field, or when the magnetic field around it changes. A way of remembering the direction of the force when a current flows in a magnetic field. The thumb shows the direction of the force, the first finger shows the direction of the magnetic field (N to S) and the second finger shows the current (+ to ). To create. For example, a wire in a changing magnetic field has a current induced in it. A piece of material that becomes a magnet because it is in the magnetic field of another magnet. The area around a magnet where it can affect magnetic materials or induce a current. A way of describing the strength of a magnetic field. It is measured in teslas (T). CP10-11 Magnetism and Induction What are permanent and induced magnets and how can we represent fields? How do magnetic fields interact? How can we transform electricity and why is this important? Did you know? The aurora borealis occurs when charged particles flowing out from the Sun become trapped by the Earth s magnetic field and enter the Earth s atmosphere near the North Pole. These particles collide with atoms in the atmosphere, and the atoms gain energy. This energy is then emitted by the atoms as light. Key Term magnetic material motor effect national grid permanent magnet plotting compass potential difference solenoid step-down transformer step-up transformer temporary magnet tesla (T) transformer transmission lines A material, such as iron, that is attracted to a magnet. The force experienced by a wire carrying a current that is placed in a magnetic field. The system of wires and transformers that distributes electricity around the country. A magnet that is always magnetic, such as a bar magnet. A small compass used to find the shape of a magnetic field. The difference in the energy carried by electrons before and after they have flowed through a component. Another term for voltage. A coil of wire with electricity flowing in it. Also called an electromagnet. A transformer that reduces the voltage. A transformer that increases the voltage. A magnet that is not always magnetic, such as an electromagnet or an induced magnet. The unit for magnetic flux density, also given as newtons per ampere metre (N/A m). A device that can change the voltage of an electricity supply. The wires (overhead or underground) that take electricity from power stations to towns and cities.

11 Key Term absolute zero The temperature at which the pressure of a gas drops to zero and the particles stop moving. It is 273 C or 0 K. The changing of matter from one state to change of state another, for example from solid to liquid. chemical change compress conserved density direct proportion elastic extension A change that results in the formation of new substances. To squash something together to make it shorter or smaller. A quantity that is kept the same throughout, for example a substance does not change mass when it changes state. The mass of a substance per unit volume. It has units such as kg/m 3 or g/cm 3. A linear relationship in which one variable doubles as the other does. An elastic material changes shape when there is a force on it but returns to its original shape when the force is removed. The amount by which a spring or other stretchy material has stretched. It is worked out from the stretched length minus the original length. CP12-13 Particle Model How can we explain densities of substances? What is specific heat capacity and specific latent heat? How can we measure temperature? Did you know? Dry ice is often used in theatres or concerts to produce fog that creeps along the floor. Dry ice is actually frozen carbon dioxide that sublimates (changes from a solid to a gas) at Key Term Kelvin temperature scale atures relative to absolute zero. A temperature scale that measures temper- A term used to describe energy when it is kinetic energy stored in moving things. The model that explains the properties of kinetic theory different states of matter in terms of the movement of particles. A relationship between two variables linear relationship linear relationship the line does not have to shown by a straight line on a graph. For a go through the origin. non-linear relationship does not produce a straight line on a graph. A relationship between two variables that A change in which no new substances are physical change formed, such as changes of state. The force on a certain area. It is measured pressure in pascals or N/m 2. specific heat The energy needed to raise the temperature of 1 kg of a substance by 1 C. capacity specific latent The energy taken in or released when 1 kg heat of a substance changes state. A measure of how stiff a spring is. The spring constant spring constant is the force needed to stretch a spring by 1 m. inelastic kelvin (K) An inelastic material changes shape when there is a force on it but does not return to its original shape when the force is removed. The unit in the Kelvin temperature scale. One kelvin (1 K) is the same temperature interval as 1 C.