physics paper 1 year 10 EOY

accelerate

to increase speed

acceleration

the rate of change of velocity per unit time, measured in m/s², calculated by the formula acceleration = change in velocity ÷ time taken

alternating current (AC)

an electric current that regularly changes direction, typically used in mains electricity

amplitude

the maximum displacement of particles in a wave from their rest position, related to the wave's energy

atom

the smallest unit of an element, made of protons, neutrons, and electrons

atomic number

the number of protons in the nucleus of an atom

battery

two or more cells connected together to provide a potential difference

beta particle

a high-speed electron emitted from the nucleus during radioactive decay

charge

a property of matter that causes it to experience a force in an electric field, measured in coulombs (C)

circuit breaker

a safety device that automatically breaks the circuit when excessive current flows

current

the flow of electric charge per unit time, measured in amperes (A), calculated by current = charge ÷ time

density

mass per unit volume of a substance, measured in kg/m³, calculated by density = mass ÷ volume

displacement

the distance moved in a straight line in a specific direction from a starting point

distance

how far an object moves, not including direction

efficiency

the percentage of input energy transferred usefully, calculated by (useful output ÷ total input) × 100

elastic potential energy

energy stored in a stretched or compressed object, calculated by ½ × spring constant × extension²

electron

a negatively charged subatomic particle found in orbitals around the nucleus

energy

the capacity to do work, measured in joules (J)

fossil fuels

natural fuels like coal, oil, and gas formed from the remains of living organisms, non-renewable and emit carbon dioxide when burned

frequency

number of wave cycles per second, measured in hertz (Hz)

fuses

safety devices with a thin wire that melts if current exceeds a limit, breaking the circuit

gamma radiation

high-energy electromagnetic radiation emitted from atomic nuclei, very penetrating

gravitational field strength

the force per kilogram of mass in a gravitational field, measured in N/kg

gravitational potential energy

energy stored in an object due to its position in a gravitational field, calculated by GPE = mass × gravitational field strength × height

half-life

the time taken for half the radioactive nuclei in a sample to decay

ion

an atom or molecule with a net electric charge due to loss or gain of electrons

ionising radiation

radiation that can remove electrons from atoms, creating ions, includes alpha, beta, and gamma

kinetic energy

energy an object has due to its motion, calculated by KE = ½ × mass × velocity²

longitudinal wave

a wave where particle vibration is parallel to the direction of wave travel, e.g., sound

mass

the amount of matter in an object, measured in kilograms (kg)

momentum

mass × velocity, a conserved quantity in closed systems

neutron

a neutral subatomic particle found in the nucleus with approximately the same mass as a proton

Ohm's Law

current through a conductor is directly proportional to voltage across it, provided temperature is constant, V = I × R

permanent magnet

an object that produces its own magnetic field

potential difference

the work done per coulomb of charge, measured in volts (V), also called voltage

power

the rate of energy transfer or work done, measured in watts (W), P = E ÷ t or P = I × V

proton

a positively charged subatomic particle found in the nucleus

radiation

transfer of energy as waves or particles, particularly from radioactive decay

radioactive decay

the spontaneous breakdown of an unstable atomic nucleus releasing particles or energy

rarefaction

the region in a longitudinal wave where particles are furthest apart

reflection

the bouncing back of a wave at a boundary

refraction

the bending of a wave as it passes into a medium with a different speed

resistance

opposition to the flow of electric current, measured in ohms (Ω), R = V ÷ I

resultant force

a single force that has the same effect as all the forces acting on an object combined

scalar quantity

a quantity with magnitude only (e.g. speed, distance)

series circuit

a circuit with components connected one after another so the same current flows through all

speed

the rate of change of distance, measured in m/s, speed = distance ÷ time

specific heat capacity

the energy required to raise the temperature of 1 kg of a substance by 1°C, measured in J/kg°C

spring constant

a measure of stiffness of a spring, calculated by force = spring constant × extension

terminal velocity

the maximum constant speed an object reaches when the force of gravity is balanced by resistive forces

thermal energy

internal energy of a substance due to the kinetic energy of its particles

transverse wave

a wave where particles vibrate perpendicular to wave direction, e.g., light

velocity

speed in a given direction, a vector quantity

vector quantity

a quantity with both magnitude and direction (e.g. velocity, force)

voltage

see potential difference

watt

unit of power, 1 W = 1 J/s

wavelength

the distance between two corresponding points on a wave, e.g., crest to crest

work done

energy transferred by a force, calculated by work = force × distance moved in direction of force

acceleration due to gravity

the acceleration experienced by an object in free fall near Earth's surface, caused by Earth's gravitational field, typically approximated as 9.8 m/s²

alternating voltage

a voltage that reverses its direction regularly in an alternating current circuit, such as UK mains electricity which alternates at 50 Hz

atomic mass number

the total number of protons and neutrons in the nucleus of an atom, used to determine the isotope of an element

background radiation

the low-level, natural ionising radiation present in the environment from cosmic rays, rocks, soil, and living things

braking distance

the distance a vehicle travels after the brakes are applied until it stops, affected by road surface, brake condition, and tyre grip

centripetal force

a resultant force that acts towards the centre of a circle when an object moves in a circular path, responsible for changing the direction of the object's velocity

charge conservation

the principle that electric charge cannot be created or destroyed in an isolated system, only transferred

compressions

the regions in a longitudinal wave where particles are closest together, forming areas of high pressure

conduction

the transfer of thermal energy through a substance by the vibration and movement of its particles, without movement of the substance itself

convection

the transfer of thermal energy in a fluid (liquid or gas) where warmer regions rise and cooler regions sink due to differences in density

cost of electricity

calculated by multiplying power (in kilowatts) by time (in hours) and then by the cost per unit, often measured in kilowatt-hours (kWh)

critical angle

the minimum angle of incidence at which total internal reflection occurs when a wave passes from a more dense to a less dense medium

current direction (conventional)

the direction in which positive charges would flow, from the positive terminal to the negative terminal of a power source

charges

would flow, from the positive terminal to the negative terminal of a power source, even though electrons flow the opposite way

decay curve

a graph showing how the activity of a radioactive substance decreases over time, typically exponential in shape

diffraction

the spreading of waves around a barrier or through a gap, most noticeable when the wavelength is similar in size to the gap

diode

an electrical component that allows current to flow in only one direction, used for rectification of AC to DC

displacement (wave)

the distance a point on the wave has moved from its undisturbed position, can be positive or negative depending on direction

drag force

a resistive force acting opposite to the motion of an object through a fluid (gas or liquid), often increases with speed

earth wire

a safety wire in a plug or appliance that provides a path to ground for electrical current in case of a fault, preventing electric shocks

elastic limit

the maximum force that can be applied to an object without permanently deforming it

electromagnetic spectrum

the range of all types of electromagnetic radiation, ordered by wavelength or frequency, including radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays

electromagnet

a temporary magnet created when current flows through a wire wound around a magnetic core, strength depends on current and number of coils

electromotive force (emf)

the maximum potential difference provided by a power supply when no current flows, measured in volts

energy stores

different forms in which energy can be held, including kinetic, thermal, chemical, gravitational potential, elastic potential, nuclear, and magnetic

energy transfer diagrams

visual representations showing how energy moves from one store to another, often including wasted and useful energy

equilibrium

the state in which all the forces acting on an object are balanced, resulting in no change in motion

exposure (radiation)

the measure of the amount of ionising radiation energy absorbed per unit mass of tissue, often leads to increased health risks

filament lamp

a type of light bulb that uses a coiled wire (usually tungsten) which heats up and emits light when electric current passes through, resistance increases with temperature

fuse rating

the maximum current a fuse can safely carry before melting, chosen slightly above the normal operating current of a device

geiger-müller tube

a device used to detect ionising radiation by producing an electrical signal when radiation enters a gas-filled tube

gravitational field

a region in which a mass experiences a force due to gravity, the strength is represented by gravitational field strength (N/kg)

half-thickness

the thickness of a material needed to reduce the intensity of gamma radiation by half, depends on material and energy of radiation

Hooke's Law

the law stating that the extension of a spring is directly proportional to the force applied, provided the elastic limit is not exceeded, F = kx

induced charge

electric charge that appears on an object because it is placed in an electric field, without direct contact with another charged object

induced magnet

a material that becomes magnetised when placed in a magnetic field, but loses its magnetism when the field is removed

inertia

the tendency of an object to resist a change in its motion, directly related to its mass

internal energy

the total kinetic and potential energy of the particles within a substance, affected by temperature and state changes

ionisation

the process by which an atom or molecule gains or loses electrons to form ions, commonly caused by radiation

kilowatt-hour

a unit of energy equal to

ion formation

to form ions, commonly caused by radiation

kilowatt-hour

a unit of energy equal to 1000 watts used for 1 hour, commonly used for measuring domestic electricity usage