PAPER 1 GCSE Flashcards
How to measure volume of liquids
Graduated cylinder / measuring cylinder
How to measure volume of irregular solid
Graduated cylinder and eureka can
How to measure volume of a regular solid
Ruler
Pressure at a point in a gas or loquid at rest acts
Equally in all directions
Determine acceleration from velocity - time graph
Gradient
Determine distance travelled from velocity - time graph
Area between graph and time axis
Advantages of parallel circuits
Components (e.g. bulbs) may be switched on/off independently.
If one component breaks, current can still flow through the other parts of the circuit.
Bulbs maintain a similar brightness
Advantages of series circuits
Fewer wires, cheaper and easier to assemble.
Uses less power
In series circuits as the voltage increases…
The current also increases
In series circuit, the more components in a circuit…
The lower the current
As you increase the resistance in a circuit,
The current will decrease
LDR as light increases
As light increases, resistance decreases
Thermistor with temperature
As temperature increases, resistance decreases
What is current
The rate of flow of charge
What is electric current
The flow of negatively charged electrons in solid metallic conductors
Voltage across two components connected in parallel is
The same
What is voltage
Energy transferred per unit charge passed
What is the volt
Joule per coulomb
What are transverse waves
A wave that vibrates or oscillates at right angles (perpendicular) to the direction in which energy is transferred/ the wave is moving.
Eg. Light
What are longitudinal waves
A wave that vibrates or oscillates at parallel to (along) the direction in which energy is transferred/ the wave is moving.
Eg. Sound
What is wavefront
Created by overlapping lots of different waves. A wavefront is where all the vibrations are in phase and the same distance from the source.
What is amplitude
The maximum displacement of particles from their equilibrium position.
What is wavelength
The distance between a particular point on one cycle of the wave and the same point on the next cycle
What is frequency
The number of waves passing a particular point per second. Is measured in Hertz (Hz).
What is time period
The time it takes for one complete wave to pass a particular point.
What do waves transfer
energy and information without transferring matter
what is the doppler effect
the doppler effect is a change in the observed frequency and wavelength of a wave when its source is moving relative to an observer
when a car is moving, wavefronts of the sound are no longer evenly spaced.
if the source is moving away from you the wavelengths increase and the frequency decreases
this is because the wavefronts compress together in front of the moving source and spread out behind the moving source
Principle of conservation of energy
In any process energy is never created or destroyed. (It is just transferred from one store to another.)
Conduction is
the transfer of thermal energy through a substance by the vibration of the atoms within the substance. Metals are good conductors because they have free electrons that can move easily through the metal, making the transfer of energy happen faster
Convection occurs in
occurs in a liquid or gas. These expand when heated because the particles move faster and take up more volume – the particles remain the same size but become further apart. The hot liquid or gas is less dense, so it rises into colder areas. The denser, colder liquid or gas falls into the warm areas. In this way, convection currents are set up which transfer heat from place to place.
Thermal radiation is
the transfer of energy by infrared (IR) waves. These travel very quickly in straight lines.
how emission and absorption of radiation are related to surface and temperature
Light, shiny surfaces are good reflectors of IR and so are poor at absorbing it.
– Dark, matt surfaces are poor reflectors and good at absorbing IR.
– This means that placed next to a heat source, a dark object would heat up faster than a light one.
– Dark matt surfaces are also best at emitting IR. This means that a hot object with a light shiny surface will emit less IR than a dark matt object at the same temperature.
– Hotter objects emit more IR per second. The type of EM wave emitted also changes with temperature – the higher the temperature the higher the frequency of EM wave emitted.
explain ways of reducing unwanted energy transfer, such as insulation
A good insulating material is a poor conductor that contains trapped air, e.g. foam, feathers, glass fibre. Being a poor conductor (non-metal) prevents heat transfer by conduction and the trapped air prevents convection currents.
atomic (proton) number is
the number of protons in the nucleus of an atom
Mass (nucleon) number is
the total number of protons and neutrons in the nucleus of an atom
An isotope is
an atom of the same element, i.e. it has the same number of protons/same atomic number, but has a different number of neutrons/different mass number. Two atoms with the same atomic number but different mass numbers are isotopes
alpha (α) particles, beta (β−) particles, and gamma (γ) rays
ionising radiations emitted from unstable nuclei in a random process
Alpha ionising power
Strong
Alpha range in air
A few centimetres
Alpha is stopped by
Paper or thin card
What is an alpha particle
Helium nucleus
Beta ionising power
Moderate
Beta range in air
About 1m
Beta is stopped by
5mm of aluminium
Beta radiation is a
Fast moving electron
Gamma ionising power
Very weak
Gamma range in air
At least 1km
Gamma is stopped by
10cm of lead
Gamma rays are
Electromagnetic waves
investigate the penetration powers of different types of radiation using
Detect using a Geiger Müller Tube.
Try the three different materials in order, paper then aluminium then lead.
Count rate will significantly decrease if radiation is stopped.
describe the effects on the atomic and mass numbers of a nucleus of the emission of alpha radiation
· 2 protons and 2 neutrons are lost.
· Mass number decreases by 4
· Atomic number decreases by 2
describe the effects on the atomic and mass numbers of a nucleus of the emission of beta radiation
· 1 neutron is converted to an electron (lost from the atom) and proton
· Mass number is unchanged
· Atomic number increases by 1
describe the effects on the atomic and mass numbers of a nucleus of the emission of gamma radiation
· Energy is lost from an atom in the form of an electromagnetic wave
· Mass number is unchanged
· Atomic number is unchanged
Geiger Müller detector:
When connected to a counter, the detector will be able to measure radioactivity.
Photographic film:
Radiation will cause photographic film to darken.
sources of background (ionising) radiation from Earth and space
radon in air Granit in rocks Cosmic rays Medical equipment Food and drink
activity of a radioactive source decreases
over a period of time and is
measured in becquerels.
The Half-life is
the time taken for the radioactivity of a specific isotope to fall to half its original value.
contamination is
Occurs when material that contains radioactive atoms is deposited on materials, skin, clothing, or any place where it is not desired.
irradiation is
The process by which an object is exposed to radiation.
the universe is
a large collection of billions of galaxies
a galaxy is
a large collection of billions of stars
moons orbit
planets because of gravitational forces with circular orbits
planets orbit
the Sun because of gravitational forces in slightly squashed circles (ellipses)
artificial satellites orbit
the Earth because of gravitational forces
comets orbit
the Sun because of gravitational forces with highly elliptical forces
