# Notes

## Forces and Matter

Stretching, bending or compressing an object requires more than one force. If an object has been elastically distorted it can go back to its original shape and length after the force has been removed. Inelastic distortion means that the changed shape is irreversible...

## Particle Model

In solids, there are strong forces of attraction that hold particles in a fixed, regular arrangement. The particles vibrate about these fixed positions In liquids, the forces of attraction between particles are weaker so particles are close together but can move past...

## Electromagnetic Induction

A changing magnetic field can induce a voltage in a wire and this causes current to flow. A potential difference can also be induced if a wire is moved in a magnetic field and, if this wire is in a circuit, this can allow for a current to flow. The size of the induced...

## Magnetism and the Motor Effect

A bar magnet is a permanent magnet as it is always magnetic. A magnet can always attract magnetic materials, like iron, nickel and cobalt. The space around the magnet is called the magnetic field, where magnetic materials experience a force. Opposite magnetic poles...

## Electricity and Circuits

Circuits and Resistance The atom consists of a central nucleus containing protons (relative mass 1, relative charge +1) and neutrons (relative mass 1, relative charge 0), surrounded by shells of electrons (relative mass 1/1835, relative charge +1). Metals have...

## Static Electricity

Insulators like plastics can collect a charge through friction and the transfer of electrons, but this charge cannot be transferred and is therefore static. The material which gains electrons becomes negatively charged while the material which loses electrons has an...

## Forces and their Effects

For 9.2 see Topic 2 and 9.10, see Topic 3 A force is a push or pull on an object that is caused by interaction. Interaction by contact means that both objects need to touch by friction or normal contact force. Interaction without contact is caused by interacting...

## Energy – Forces Doing Work

For 8.1-8.4, 8.8-8.11 and 8.15, see Topic 3 When a force moves an object through a distance, work is done on the object and energy has been transferred. The energy transferred is equal to the work done. When a force does work it often causes a rise in temperature as...

## Astronomy

Our solar system consists of the Sun, eight planets and their natural satellites (such as our Moon), dwarf planets, asteroids and comets. The order of the planets is Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. The planets move around the sun in...

An atom has a positively charged nucleus, consisting of protons on neutrons, surrounded by negatively charged electrons, with the nuclear radius of 1 × 10-15m compared to the size of an atom at 1 × 10-10m. JJ Thomson found that atoms have electrons with a negative...

## Light and the Electromagnetic Spectrum

CORE PRACTICAL: Investigating Refraction A – Place a piece of paper on the desk and set up the power supply, ray box and single slit so that a single ray shines across the paper B – Place a rectangular glass block on the paper and draw around it C – Shine light into...

## Waves

Wave Behaviour Waves transfer energy and information without transferring matter. There is proof of this in water and music. Dropping a twig into a calm pool of water causes ripples to form and move across the water, while the twig and the water themselves are not...

## Conservation of Energy

Gravitational Potential Energy is energy stored because of an object’s position in a gravitational field. Kinetic Energy is energy stored in moving objects where ΔGPE = Change in Gravitational Potential Energy (J), m = Mass (kg), g = Gravitational Field Strength...

## Motion and Forces

A scalar quantity, such as distance, speed, mass, energy, temperature and time, has magnitude but no specific direction. Vector quantities, such as force, velocity, displacement, weight, acceleration and momentum, have a magnitude and a direction. Speed is the rate a...