1. Motion, forces and energy

• Describe the use of rulers and measuring cylinders to find a length or a volume

• Describe how to measure a variety of time intervals using clocks and digital timers

• Determine an average value for a small distance and for a short interval of time by measuring multiples (including the period of oscillation of a pendulum)

• Understand: a scalar quantity has magnitude (size) only and that a vector quantity has magnitude and direction

• Know scalar quantities: distance, speed, time, mass, energy and temperature

• Know vector quantities: force, weight, velocity, acceleration, momentum, electric field strength and gravitational field strength

• Determine, by calculation or graphically, the resultant of two vectors at right angles, limited to forces or velocities only

• Define speed as distance travelled per unit time; recall/use: v = s/t

• Define velocity as speed in a given direction

• Recall/use: average speed = total distance travelled / total time taken

• Sketch, plot and interpret distance–time and speed–time graphs

• Determine qualitatively from given data or the shape of a distance–time graph or speed–time graph when an object is: (a) at rest (b) moving with constant speed (c) accelerating (d) decelerating

• Calculate speed from the gradient of a straight-line section of a distance–time graph

• Calculate the area under a speed–time graph to determine the distance travelled for motion with constant speed or constant acceleration

• State: the acceleration of free fall g for an object near to the surface of the Earth is approximately constant, about 9.8 m/s²

• Define acceleration as change in velocity per unit time; recall/use: a = Δv/Δt

• Determine from given data or the shape of a speed–time graph when an object is moving with: (a) constant acceleration (b) changing acceleration

• Calculate acceleration from the gradient of a speed–time graph

• Know: a deceleration is a negative acceleration and use this in calculations

• Describe the motion of objects falling in a uniform gravitational field with and without air/liquid resistance, including reference to terminal velocity

• State: mass is a measure of the quantity of matter in an object at rest relative to the observer

• State: weight is a gravitational force on an object that has mass

• Define gravitational field strength as force per unit mass; recall/use: g = W/m; know it is equivalent to acceleration of free fall

• Know: weights (and masses) may be compared using a balance

• Describe, and use the concept of, weight as the effect of a gravitational field on a mass

• Define density as mass per unit volume; recall/use: ρ = m/V

• Describe how to determine the density of a liquid, of a regularly shaped solid and of an irregularly shaped solid which sinks in a liquid (volume by displacement), including appropriate calculations

• Determine whether an object floats based on density data

• Determine whether one liquid will float on another liquid based on density data given that the liquids do not mix

• Know: forces may produce changes in the size and shape of an object

• Sketch, plot and interpret load–extension graphs for an elastic solid and describe the associated experimental procedures

• Determine the resultant of two or more forces acting along the same straight line

• Know: an object either remains at rest or continues in a straight line at constant speed unless acted on by a resultant force

• State: a resultant force may change the velocity of an object by changing its direction of motion or its speed

• Describe solid friction as the force between two surfaces that may impede motion and produce heating

• Know: friction (drag) acts on an object moving through a liquid

• Know: friction (drag) acts on an object moving through a gas (e.g. air resistance)

• Define spring constant as force per unit extension; recall/use: k = F/x

• Define and use the term ‘limit of proportionality’ for a load–extension graph and identify this point on the graph (an understanding of the elastic limit is not required)

• Recall/use: F = ma; know: the force and the acceleration are in the same direction

• Describe circular motion caused by a force perpendicular to motion: (a) greater force increases speed if mass/radius stay constant (b) greater force decreases radius if mass/speed stay constant (c) greater mass needs greater force to keep speed/radius constant (F = mv^2/r not required)

• Describe the moment of a force as a measure of its turning effect and give everyday examples

• Define the moment of a force as moment = force × perpendicular distance from the pivot; recall/use this equation

• Apply the principle of moments to situations with one force each side of the pivot, including balancing of a beam

• State that, when there is no resultant force and no resultant moment, an object is in equilibrium

• Apply the principle of moments to other situations, including those with more than one force each side of the pivot

• Describe an experiment to demonstrate that there is no resultant moment on an object in equilibrium

• State what is meant by centre of gravity

• Describe an experiment to determine the position of the centre of gravity of an irregularly shaped plane lamina

• Describe qualitatively the effect of the position of the centre of gravity on the stability of simple objects

• Define momentum as mass × velocity; recall/use: p = mv

• Define impulse as force × time for which force acts; recall/use: impulse = F∆t = ∆(mv)

• Apply the principle of the conservation of momentum to solve simple problems in one dimension

• Define resultant force as change in momentum per unit time; recall/use: F = Δp/Δt

1.7.1.1Energy may be stored as kinetic

• State: energy may be stored as kinetic, gravitational potential, chemical, elastic (strain), nuclear, electrostatic and internal (thermal)

1.7.1.2Energy is transferred between stores

• Describe how energy is transferred between stores during events and processes, including examples of transfer by forces (mechanical work done), electrical currents (electrical work done), heating, and by electromagnetic, sound and other waves

1.7.1.3Principle of the conservation of

• Know the principle of the conservation of energy and apply this principle to simple examples including the interpretation of simple flow diagrams

1.7.1.4Kinetic energy: Ek = 1/2 mv^2

• Recall/use kinetic energy: Ek = 1/2 mv^2

1.7.1.5Recall/use: for the change in

• Recall/use: for the change in gravitational potential energy ∆Ep = mg∆h

1.7.1.6Principle of the conservation of

• Know the principle of the conservation of energy and apply this principle to complex examples involving multiple stages, including the interpretation of Sankey diagrams

• Understand: mechanical or electrical work done is equal to the energy transferred

• Recall/use: for mechanical working W = Fd = ∆E

• Describe useful energy/electrical power sources: (a) fossil fuels (b) biofuels (c) water: waves, tides and hydroelectric dams (d) geothermal resources (e) nuclear fuel (f) sunlight for solar cells (g) infrared/other EM waves for solar water heating and wind energy, including boilers, turbines and generators where used

• Describe advantages and disadvantages of each method in terms of renewability, availability, reliability, scale and environmental impact

• Understand, qualitatively, the concept of efficiency of energy transfer

• Know: radiation from the Sun is the main source of energy for all our energy resources except geothermal, nuclear and tidal

• Know: energy is released by nuclear fusion in the Sun

• Know: research is being carried out to investigate how energy released by nuclear fusion can be used to produce electrical energy on a large scale

• Define and use efficiency: (a) efficiency = useful energy output / total energy input × 100% (b) efficiency = useful power output / total power input × 100%

• Define power as work done per unit time or energy transferred per unit time; recall/use: P = W/t and P = ΔE/t

• Define pressure as force per unit area; recall/use: p = F/A

• Describe how pressure varies with force and area in the context of everyday examples

• Describe qualitatively how the pressure beneath the surface of a liquid changes with depth and density of the liquid

• Recall/use: for the change in pressure beneath the surface of a liquid ∆p = ρg∆h