Uniform Circular Motion

How to describe motion around a circle with angles in radians, period, frequency and angular velocity; how the speed along the circle is linked to the angular velocity by v = rω; why a body moving round a circle at constant speed is still accelerating towards the centre; the centripetal force that every circular motion needs, and the centrifugal effect felt in a turning vehicle; and how roundabouts, centrifuges and spin dryers use these ideas.

2

Linear Momentum, Impulse and Collisions

Momentum as mass times velocity and Newton's second law as the rate of change of momentum; impulse as the change in momentum and why seat belts, airbags and helmets save lives by making collisions last longer; the conservation of linear momentum and how it explains recoil, rockets, boats, swimmers and running; and how to analyse elastic and inelastic collisions in one dimension.

3

Renewable and Non-Renewable Energy Sources

What an energy source is and how power stations turn falling water, fuels and sunlight into electricity; the renewable sources (solar, hydro, wind, biomass and geothermal) and the non-renewable ones (fossil fuels, peat, the methane of Lake Kivu and nuclear fuel), with their advantages, disadvantages and effects on the environment; where Rwanda's electricity and cooking energy come from, using REG and NISR figures; and why the move to renewable energy matters.

4

Quantity of Heat and Heat Transfer

How much heat it takes to warm a body (Q = mcΔT), heat capacity and specific heat capacity; the principle of heat exchange and the method of mixtures; latent heat and the heating curve of water; conduction, convection and radiation and the devices that use or block them; and the linear, area and volume expansion of solids and liquids.

5

Atmospheric Pressure and Archimedes' Principle

Evidence that the air presses on everything, the units of atmospheric pressure and how it changes with altitude and weather; the mercury and aneroid barometers, the manometer and p = hρg; how drinking straws, suckers, syringes, siphons, lift pumps and vacuum cleaners use atmospheric pressure; and Archimedes' principle, upthrust and the conditions for floating, sinking and flying balloons.

6

Electrical Power Transmission

Electromagnetic induction and how a transformer works; the turns-ratio and power equations for step-up and step-down transformers, their efficiency and energy losses; why electricity is sent across Rwanda at 110 kV and 220 kV, how P = I²R losses are kept small and how the grid steps the voltage down to 400 V and 230 V; and the dangers of high-voltage power lines and how to stay safe near them.

7

Basic Electrical Wiring and Installation

Resistors in series, in parallel and in combination; electromotive force, internal resistance and cells in series and parallel; electrical energy, power and the cost of electricity in kWh at REG's tariff; how a house is wired, from the meter and consumer unit to lighting and socket circuits, with the colour code, components, tools and procedure; and electrical safety in the home: fuses, circuit breakers, earthing and residual-current devices.

8

Refraction of Light

How light bends when it crosses from one transparent material into another: refractive index and Snell's law, the parallel-sided block and apparent depth, critical angle, total internal reflection and optical fibres, converging and diverging lenses with ray diagrams, the lens equation and power, lens defects, and refraction and dispersion by a prism.

9

Telecommunication Channels

How information is carried over a distance: the parts of a communication system, analogue and digital signals and why digital has largely taken over, the wired channels (wire pairs, coaxial cable and optical fibre), and the wireless channels, from the radio bands of the electromagnetic spectrum, AM and FM, to satellites and mobile networks.

10

Basic Electronic Components

What electronics is and how its components are drawn: active and passive components and their IEC symbols, resistors and the colour code, capacitors, diodes, LEDs and rectifiers, light and temperature sensors, the transistor as a switch and as an amplifier, and the components found on a computer motherboard, with electrical safety throughout.

Units