Speed

• Speed is how much distance is covered per unit time
• Speed can be calculated using the following equation: Speed (m/s)=Distance (m)Time (s)
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• The SI unit for speed is m/s
• If an object is stationary its speed is 0 m/s
• Average speed is the overall distance travelled divided by the overall time for a journey
• Acceleration describes how quickly a speed is changing (speeding up or slowing down)
• Relative motion describes how different observers judge speed differently if they are in motion too
• If an observer is stationary, the relative motion of the moving object will be the same as its actual speed
• If an observer is travelling in the same direction as the moving object, the relative motion is the difference in their speeds and the object will seem to be moving more slowly
• If an observer is travelling in the opposite direction as the moving object, the relative motion is their speeds added together and the object will seem to be moving faster

Distance-Time Graphs

• A distance-time graph can be used to describe an objects motion
• A horizontal line represents a stationary object (0 m/s)
• A straight line represents an object moving at the same speed
• A curved line describes an object accelerating
• A line that returns to the x-axis (distance = 0) shows an object that has returned to its starting position
• The gradient (slope) of the distance-time graph is the object's speed because this is distance/time
• The steeper the gradient, the greater the speed of an object

Pressure

• Pressure is the force applied per unit area
• Pressure can be calculated using the following equation: Pressure(N/m2)=Force (N)Area (m2)
  
• Pressure is increased by a larger force and decreased by larger area

Moments

• A moment is the turning effect of a force
• The moment of a force can be calculated using the following equation: Moment (Nm) = Force (N)× Perpendicular distance from pivot (m)

Disciplinary Knowledge

• Interpret a line (scatter) graph
• Draw conclusions from given observations.
• Draw conclusions from a graph
• Draw conclusions from a table
• Understand the terms mean, mode and median
• Calculate areas of triangles and rectangles, surface areas and volumes of cubes
• Recognise the importance of scientific quantities and understand how they are determined.

Practical Skills

• Measure time accurately
• Measure motion, including determination of speed and rate of change of speed (acceleration/deceleration)
• Plot two variables from experimental or other data.

Magnetism

• The magnetic force is a non-contact force exerted by magnetic materials on each other  
• Iron, cobalt and nickel are magnetic materials, and steel is an alloy of iron so it is also a magnetic material
• Bar magnets have a North pole and a South pole
• The poles of a magnet are where the magnetic force is the strongest
• Opposite poles attract and like poles repel
• Permanent magnets are magnetic all the time
• Magnetic materials and the Earth create magnetic fields around them
• A magnetic field is the area around a magnet that is affected by the non-contact magnetic force
• Magnetic field lines are used to describe the strength and direction of the magnetic field
• The direction of the magnetic field at any point is given by the direction of the force that would act on another north pole placed at that point  
• Field lines flow from the North pole to the South pole
• Closer field lines demonstrate that the magnetic force is stronger
• The Earth has a magnetic field
• The Earth behaves like it has a giant bar magnet inside it, because of currents of molten iron and nickel in its core
• A compass will point to Earth's North (magnetic) pole which is different to Earth's geographic North pole

Electromagnets

• Induced magnets are materials that become magnetic when placed in a magnetic field and lose their magnetism when removed
• When a current flows through a conducting wire a magnetic field is produced around the wire
• A solenoid is a coil of wire with a current flowing through it
• An electromagnet is a solenoid with an iron core
• The strength of the magnetic field around a solenoid is increased by adding more turns in the coil, adding a magnetic material as a core or increasing the current
• The strength of the magnetic field depends on the current through the wire, the number of turns in the coil, the core material and the distance from the wire
• An electromagnet can be turned off when there is no current flowing through it

Practical skills

Visualise and represent 2D and 3D forms including 2 dimensional representations of 3D objects

Resistance

• Resistance decreases current in a circuit
• Resistance is measured in Ohms (Ω)
• The greater the resistance, the slower the current
• Resistance is added by all components, including the wires themselves
• Electrical conductors have low resistance, which means current easily flows through them
• Most metals are electrical conductors
• Electrical insulators have high resistance, which means current does not easily flow through them
• Non-metals such as wood and plastic are electrical insulators
• A resistor can be any component that provides resistance in a circuit
• A fixed resistor has a resistance that cannot change
• A variable resistor has a resistance that can be increased or decreased
• Changing the resistance of a variable resistor changes the current
• Variable resistors are found in circuits where the current needs to be changed, such as dimmer switches

Ohm’s Law

• Current through a component depends on both resistance of the component and voltage cross the component
• Increasing the resistance decreases the current
• Increasing the voltage increases the current
• Current can be calculated using the following equation: Current (A)=Voltage (V)Resistance (Ω)
• Resistance can be calculated using the following equation: Resistance (Ω)=Voltage (V)Current (A)
• Voltage can be calculated using the following equation: Voltage (V) = Current (A) x Resistance (Ω)
• A longer wire has a greater resistance
• Resistance in series is the sum of all the individual resistors
• Resistance in parallel is less than the branch with the lowest resistance

Disciplinary Knowledge

• Change the subject of an equation
• Describe mathematical relationships in terms of proportionality
• Describe and explain specified examples of the technological applications of science.
• Describe and evaluate, with the help of data, methods that can be used to tackle problems caused by human impacts on the environment.

Practical Skills

• Use of appropriate apparatus to measure current, potential difference (voltage) and resistance, and to explore the characteristics of a variety of circuit elements
• Use of circuit diagrams to construct and check series and parallel circuits including a variety of common circuit elements