2.14 know and use the relationship between voltage, current and resistance voltage = current × resistance V = I × R
Notes
2.15 understand that current is the rate of flow of charge
2.15 understand that current is the rate of flow of charge The size of an electric current indicates the rate at which charge flows. Charge(Q) is measured in coulombs (C). Current is measured in amperes (A). If 1 C of charge flows along a wire every second the current...
2.16 know and use the relationship between charge, current and time
2.16 know and use the relationship between charge, current and time charge = current × time Q = I × t
2.17 know that electric current in solid metallic conductors is a flow of negatively charged electrons
2.17 know that electric current in solid metallic conductors is a flow of negatively charged electrons Current is the flow of charge. One coulomb of charge is equivalent of the charge carried by approximately six million, million, million (6 x 1018) negative electrons.
2.18 understand that
2.18 understand that voltage is the energy transferred per unit charge passed the volt is a joule per coulomb.
2.25 explain some uses of electrostatic charges, eg in photocopiers and inkjet printers
2.25 explain some uses of electrostatic charges, eg in photocopiers and inkjet printers Electrostatic charges can be used in electrostatic paint spraying, inkjet printers, photocopiers, electrostatic precipitators etc. In inject printers inks are given negative...
2.24 explain the potential dangers of electrostatic charges, eg when fuelling aircraft and tankers
2.24 explain the potential dangers of electrostatic charges, eg when fuelling aircraft and tankers In some situations the presence of static electricity can be a disadvantage. As aircraft fly through the air, they can become charged with static electricity. As the...
2.23 explain electrostatic phenomena in terms of the movement of electrons
2.23 explain electrostatic phenomena in terms of the movement of electrons An electrostatic phenomenon is an event where electricity has a special effect, for example a static shock. Electrons move from one material to another. Materials with a negative charge will...
2.22 understand that there are forces of attraction between unlike charges and forces of repulsion between like charges
2.22 understand that there are forces of attraction between unlike charges and forces of repulsion between like charges Similar charges repel each other and unlike charges attract each other. The attraction and repulsion occurs because of electrostatic force.
2.21 explain that positive and negative electrostatic charges are produced on materials by the loss and gain of electrons
2.21 explain that positive and negative electrostatic charges are produced on materials by the loss and gain of electrons If two material are rubbed together electrons will be transferred. The one that gains electrons will be negatively charged and the one that losses...
2.5 know and use the relationship
2.5 know and use the relationship power = current × voltage P = I × V and apply the relationship to the selection of appropriate fuses Power is amount that represents how much voltage or energy is converted every second. It is calculated using this equation: Power, P...
2.19 identify common materials which are electrical conductors or insulators, including metals and plastics
2.19 identify common materials which are electrical conductors or insulators, including metals and plastics Conductors: Electrical conductors are materials that allow current to pass through them. Conductors have free electron diffusion to pass current. Metals like...
2.7 understand the difference between mains electricity being alternating current (a.c.) and direct current (d.c.) being supplied by a cell or battery.
2.7 understand the difference between mains electricity being alternating current (a.c.) and direct current (d.c.) being supplied by a cell or battery. The mains electricity supply provides alternating current (a.c.). Alternating current constantly changes their...
2.6 use the relationship between energy transferred, current, voltage and time
2.6 use the relationship between energy transferred, current, voltage and time energy transferred = current × voltage × time E = I × V × t The power of an appliance (P) tells you how much energy it converts each second. This means that the total energy (E) converted...
1.32 understand gravitational field strength, g, and recall that it is different on other planets and the moon from that on the Earth
1.32 understand gravitational field strength, g, and recall that it is different on other planets and the moon from that on the Earth The strength of gravity on a planet or moon is called its gravitational field strength. But this force depends upon The masses of the...
1.33 explain that gravitational force
1.33 explain that gravitational force causes moons to orbit planets causes the planets to orbit the sun causes artificial satellites to orbit the Earth causes comets to orbit the sun Planets are held in orbit by the gravitional pull of the Sun. Similarly comets orbit...
2.1 use the following units: ampere (A), coulomb (C), joule (J), ohm (Ω), second (s), volt (V), watt (W).
2.1 use the following units: ampere (A), coulomb (C), joule (J), ohm (Ω), second (s), volt (V), watt (W). Unit of current: ampere (A) Unit of charge: coulomb (C) Unit of energy: Joule (J) Unit of resistance: ohm (Ω) Unit of time: second (s) Unit of voltage or...
2.11 describe the qualitative effect of changing resistance on the current in a circuit
2.11 describe the qualitative effect of changing resistance on the current in a circuit Resistance is inversely proportional to current. Higher resistance means lower current and higher current means lower resistance. In other words resistance is the opposite of...
2.10 describe how current varies with voltage in wires, resistors, metal filament lamps and diodes, and how this can be investigated experimentally
2.10 describe how current varies with voltage in wires, resistors, metal filament lamps and diodes, and how this can be investigated experimentally In parallel circuit, current varies with the resistance and voltage. Voltage are same at all branches. This circuit...
2.9 understand that the current in a series circuit depends on the applied voltage and the number and nature of other components
2.9 understand that the current in a series circuit depends on the applied voltage and the number and nature of other components In a series circuit the current is the same in all parts. Current is not used up as it passes around a circuit. The size of the current is...
2.8 explain why a series or parallel circuit is more appropriate for particular applications, including domestic lighting
2.8 explain why a series or parallel circuit is more appropriate for particular applications, including domestic lighting Series Circuit: one switch can turn off the components on and off together if one bulb ( or other component) breaks, it causes a gap in the...
1.29 describe experiments to investigate how extension varies with applied force for helical springs, metal wires and rubber bands
1.29 describe experiments to investigate how extension varies with applied force for helical springs, metal wires and rubber bands Experiment: Investigating extension with applied force in spring Apparatus: Spring/Wire/Rubber-band, Scale, Some masses, Clamp and stand,...
1.28 understand that the upward forces on a light beam, supported at its ends, vary with the position of a heavy object placed on the beam
1.28 understand that the upward forces on a light beam, supported at its ends, vary with the position of a heavy object placed on the beam An object weighing 400 N is placed in the middle of the beam. The beam is not moving,so the upward and downward forces must be...
1.31 describe elastic behaviour as the ability of a material to recover its original shape after the forces causing deformation have been removed.
1.31 describe elastic behaviour as the ability of a material to recover its original shape after the forces causing deformation have been removed. Objects showing elastic behaviour has the ability to return to its original shape after the forces causing its shape are...
1.30 understand that the initial linear region of a force-extension graph is associated with Hooke’s law
1.30 understand that the initial linear region of a force-extension graph is associated with Hooke’s law Hooke’s law, “Within the elastic limit, extension is directly proportional to the load i.e. e α f” Hooke measured the increase in length (extension) produced by...
1.27 know and use the principle of moments for a simple system of parallel forces acting in one plane
1.27 know and use the principle of moments for a simple system of parallel forces acting in one plane Here, the pivot is placed in the centre of the beam which balances it upon the pivot. All the weight is acting upon it. If the pivot is moved leftwards, the distance...
1.26 recall that the weight of a body acts through its center of gravity
1.26 recall that the weight of a body acts through its centre of gravity The centre of gravity of an object is the point where the whole weight appears to act. So if we support the centre of gravity of the object, the object wont fall no matter how wide it is. Because...
1.22 use the conservation of momentum to calculate the mass, velocity or momentum of objects
1.22 use the conservation of momentum to calculate the mass, velocity or momentum of objects Force x time = increase in momentum If a moving object hits another slow or stationary object, it will result an equal force to both of the objects (according to Newton’s...
1.23 use the relationship between force, change in momentum and time taken
1.23 use the relationship between force, change in momentum and time taken Initial momentum of object= mu Final momentum= mv Therefore increase in momentum = mv-mu Rate of increase of momentum= (mv-mu)/t (mv – mu)/t m(v-u)/t ma=Force Force = Rate of increase of...
1.24 demonstrate an understanding of Newton’s third law
1.24 demonstrate an understanding of Newton’s third law Newton’s thirds law: “For every action there is an equal and opposite reaction.” Newton’s third law states four characteristics of forces: Forces always occur in pairs (action and reaction force.) The action and...
1.25 know and use the relationship between the moment of a force and its distance from the pivot
1.25 know and use the relationship between the moment of a force and its distance from the pivot moment = force × perpendicular distance from the pivot moment =F x d The turning effect of a force about a hinge or pivot is called its moment. It is measured in Newton...
1.17 describe the forces acting on falling objects and explain why falling objects reach a terminal velo
1.17 describe the forces acting on falling objects and explain why falling objects reach a terminal velocity In a free falling object two types of force acts: Drag and Weight. The size of the drag force acting on an object depends on its shape and its speed. If the...
1.18 describe experiments to investigate the forces acting on falling objects, such as sycamore seeds or parachutes
1.18 describe experiments to investigate the forces acting on falling objects, such as sycamore seeds or parachutes Experiment: Measuring the force of a falling ball using light gate Apparatus required: Cylinder, light gate, data logger, electric balance First, we...
1.19 describe the factors affecting vehicle stopping distance including speed, mass, road condition and reaction time
1.19 describe the factors affecting vehicle stopping distance including speed, mass, road condition and reaction time The stopping distance is the sum of Thinking distance and Braking distance. Thinking Distance: The distance travelled after seeing an obstacle and...
1.20 know and use the relationship between momentum, mass and velocity
1.20 know and use the relationship between momentum, mass and velocity Momentum is a quantity possessed by masses in motion. Momentum is measure of how difficult it is to stop something that is moving. We calculate the momentum of a moving object using the formula:...
1.21 use the idea of momentum to explain safety features
1.21 use the idea of momentum to explain safety features Objects in a car have mass, speed and direction. If the object, such as a person, is not secured in the car they will continue moving in the same direction (forward) with the same speed (the speed the car was...
1.13 find the resultant force of forces that act along a line
1.13 find the resultant force of forces that act along a line Forces which act along a straight line can be added if the forces are in the same direction or subtracted if the forces are in the opposite direction. The force that you get after adding or subtracting is...
1.15 know and use the relationship between unbalanced force, mass and acceleration
1.15 know and use the relationship between unbalanced force, mass and acceleration Balanced and Unbalanced force: When a force acting on an object is equal to the force opposing the object the forces are “balanced.”In this case the object will not move. If a force...
1.16 know and use the relationship between weight, mass and g
1.16 know and use the relationship between weight, mass and g Weight is the pull of earth. To calculate it, use the formula: Weight = mass x gravitional acceleration W =mg In earth g= 10 m/s2 if there is no opposite force.
1.10 identify different types of force such as gravitational or electrostatic
1.10 identify different types of force such as gravitational or electrostatic Different sorts of Force: Gravitional force or weight: The pull of earth due to gravity. Normal Reaction: Simple reaction that stops something when to apply force to it. E.g.: A book is kept...
1.11 distinguish between vector and scalar quantities
1.11 distinguish between vector and scalar quantities Scalar quantities are physical quantities that have magnitude only. Vector quantities however are physical quantities that possess both magnitude as well as direction. Scalar Vector Mass Displacement Time Velocity...
1.12 understand that force is a vector quantity
1.12 understand that force is a vector quantity Force is a vector quantity due to the following reasons - It has magnitude i.e has the value of its size. It has direction. When applied force, an object moves with particular motion in a fixed direction. E.g:...
1.14 understand that friction is a force that opposes motion
1.14 understand that friction is a force that opposes motion Friction is the force that causes moving objects to slow down and finally stop. The kinetic energy of the moving object is converted to heat as work is done by the friction force. Friction occurs when solid...
1.8 determine the distance traveled from the area between a velocity-time graph and the time axis.
1.8 determine the distance travelled from the area between a velocity-time graph and the time axis. Distance can be determined by finding the area under a velocity-time graph as shown below Distance travelled = area under the graph = 1/2(a+b)h = 1/2(100 + 40) x 150 =...
1.5 know and use the relationship between acceleration, velocity and time
1.5 know and use the relationship between acceleration, velocity and time Acceleration is the rate at which objects change their velocity. The rate of decease of velocity is called deceleration. It is just a negative acceleration. It is defined as follows:...
1.7 determine acceleration from the gradient of a velocity-time graph
1.7 determine acceleration from the gradient of a velocity-time graph Acceleration = gradient = (y2 - y1)/(x2 - x1 ) = (200-0)/(50-0) = 4 ms2
1.4 describe experiments to investigate the motion of everyday objects such as toy cars or tennis balls
1.4 describe experiments to investigate the motion of everyday objects such as toy cars or tennis balls Experiment: Measuring speed using light gate Attach a cart of measured length centrally to the top of the toy car. Air track ensures a frictionless way for the toy...
1.2 plot and interpret distance-time graphs
1.2 plot and interpret distance-time graphs Distance: The change of position of an object is called distance. The diagram shows an example: Diplacement: The change of position of an object in a particular direction is called displacement. This shows another object...
1.3 know and use the relationship between average speed, distance moved and time
1.3 know and use the relationship between average speed, distance moved and time Speed: Speed is defined as the rate of change of distance. In other words, speed is the distance moved per unit time. It tells us how fast or slow an object is moving. Average speed:...
1.1 use the following units: kilogram (kg), metre (m), metre/second (m/s), metre/second2 (m/s2), newton (N), second (s), newton per kilogram (N/kg), kilogram metre/second (kg m/s).
1.1 use the following units: kilogram (kg), metre (m), metre/second (m/s), metre/second2 (m/s2), newton (N), second (s), newton per kilogram (N/kg), kilogram metre/second (kg m/s). Unit of mass=Kilogram (kg) Unit of distance=Metre (m) Unit of speed or velocity= Metre...