Hydr0Gen2022-11-29T13:44:48+00:001.01 use the following units: kilogram (kg), metre (m), metre/second (m/s), metre/second^2(m/s^2), newton (N), second (s) and newton/kilogram(N/kg)
Hydr0Gen2019-06-28T08:48:05+00:001.02 use the following units: Newton metre (Nm), kilogram metre/second (kgm/s)
Hydr0Gen2022-11-29T13:32:19+00:001.04 know and use the relationship between average speed, distance moved and time taken
Hydr0Gen2022-11-29T14:21:07+00:001.05 practical: investigate the motion of everyday objects such as a toy car or tennis ball
Hydr0Gen2022-11-29T14:21:23+00:001.06 know and use the relationship between acceleration, change in velocity and time taken
Hydr0Gen2022-11-29T14:23:12+00:001.08 determine acceleration from the gradiend of a velocity-time graph
Hydr0Gen2022-11-29T14:23:29+00:001.09 determine the distance travelled from the area between a velocity-time graph and the time axis
Hydr0Gen2019-06-28T09:05:27+00:001.10 use the relationship between final speed, initial speed, aceleration and distance moved
Hydr0Gen2022-11-29T14:23:47+00:001.11 describe the effects of forces between bodies such as changes in speed, shape or direction
Hydr0Gen2022-11-29T14:24:22+00:001.12 identify different types of force such as gravitational or electrostatic
Hydr0Gen2022-11-29T14:25:22+00:001.17 know and use the relationship between unbalanced force, mass and acceleration : F = M x A
Hydr0Gen2022-11-29T14:25:35+00:001.18 know and use the relationship between weight, mass and gravitational field strength: W=mxg
Hydr0Gen2022-11-29T14:25:47+00:001.19 know that the stopping distance of a vehicle is made up of the sum of the thinking distance and the breaking distance
Hydr0Gen2022-11-29T14:26:01+00:001.20 describe the factors affecting vehicle stopping distance, including speed, mass, road condition and reaction time
Hydr0Gen2019-06-28T09:07:44+00:001.21 describe the forces acting on falling objects (explain why falling objects reach a terminal velocity)
Hydr0Gen2019-06-28T09:08:02+00:001.22 practical investigate how extension varies with applied force for helical springs, metal wires and rubber bands
Hydr0Gen2019-06-28T09:08:24+00:001.23 know the the initial linear region of a force-extension graph is associated with Hooke’s law
Hydr0Gen2019-06-28T09:08:49+00:001.24 describe elastic behaviour as the ability of a material to recover its original shape after the forces causing the deformation have been removed
Hydr0Gen2019-06-28T08:49:19+00:001.25 know and use the relationship between momentum, mass and velocity: P=m x v
Hydr0Gen2019-06-28T08:50:31+00:001.27 use the conservation of momentum to calculate the mass, velocity or momentum of objects
Hydr0Gen2019-06-28T08:52:25+00:001.28 use the relationship between force, change in momentum and time take
Hydr0Gen2019-06-28T08:53:43+00:001.30 know and use the relationship between the moment of a force and its perpendicular distance from the pivot
Hydr0Gen2019-06-27T10:59:36+00:001.31 know that the weight of a body acts through its centre of gravity
Hydr0Gen2019-06-28T08:54:22+00:001.32 use the principle of moments for a simple system of parallel forces acting in one plane
Hydr0Gen2019-06-28T08:55:03+00:001.33 understand how the upward forces on a light beam, supported at its ends, vary with the position of a heavy object placed on the beam
Hydr0Gen2022-11-29T14:27:12+00:002.01 use the following units: ampere (A), coulomb (C), joule (J), ohm (Ω), second (s), volt (V) and watt (W)
Hydr0Gen2019-06-28T08:27:39+00:002.02 understand how the use of insulation, double insulation, earthing, fuses and circuit breakers protects the device or user in a range of domestic appliances
Hydr0Gen2019-06-28T08:28:07+00:002.03 understand why a current in a resistor results in the electral transfer of energy and an increase in temperature, and how this can be used in a variety of domestic contexts
Hydr0Gen2022-11-29T14:27:26+00:002.04 know and use the relationship between power, current and voltage: and apply the relationship to the selection of appropriate fuses
Hydr0Gen2019-06-28T08:28:50+00:002.05 use the relationship between energy transferred, current, voltage and time: E= I × V × T
Hydr0Gen2022-11-29T14:27:43+00:002.06 know the difference between mains electricity being alternating current (a.c.) and direct current (d.c.) being supplied by a cell or battery
Hydr0Gen2019-06-28T08:29:36+00:002.07 explain why a series or parallel circuit is more appropriate for particular applications, including domestic lighting
Hydr0Gen2022-11-29T14:28:18+00:002.08 understand how the current in a series circuit depends on the applied voltage and the number and nature of other components
Hydr0Gen2022-11-29T14:28:28+00:002.09 describe how current varies with voltage in wires, resistors, metal filament lamps and diodes, and how to investigate this experimentally
Hydr0Gen2022-11-29T14:28:42+00:002.10 describe the qualitative effect of changing resistance on the current in a circuit
Hydr0Gen2019-06-28T07:33:24+00:002.11 describe the qualitative variation of resistance of light-dependent resistors (LDRs) with illumination and thermistors with temperature
Hydr0Gen2022-11-29T14:28:53+00:002.12 know that lamps and LEDs can be used to indicate the presence of a current in a circuit
Hydr0Gen2022-11-29T14:29:07+00:002.13 know and use the relationship between voltage, current and resistance: V = I × R
Hydr0Gen2019-06-28T07:35:48+00:002.15 know and use the relationship between charge, current and time: Q = I × t
Hydr0Gen2022-11-29T14:29:36+00:002.16 know that electric current in solid metallic conductors is a flow of negatively charged electrons
Hydr0Gen2019-06-28T07:37:04+00:002.18 know that the voltage across two components connected in parallel is the same
Hydr0Gen2022-11-29T14:29:53+00:002.19 calculate the currents, voltages and resistances of two resistive components connected in a series circuit
Hydr0Gen2019-06-28T08:43:46+00:002.20 know that: voltage is the energy transferred per unit charge passed and the volt is a joule per coulomb
Hydr0Gen2019-06-28T07:38:23+00:002.21 know and use the relationship between energy transferred, charge and voltage: E = Q × V
Hydr0Gen2019-06-28T08:44:02+00:002.22 identify common materials which are electrical conductors or insulators, including metals and plastics
Hydr0Gen2019-06-27T07:50:09+00:002.23 practical: investigate how insulating materials can be charged by friction
Hydr0Gen2019-06-27T07:50:36+00:002.24 explain how positive and negative electrostatic charges are produced on materials by the loss and gain of electrons
Hydr0Gen2019-06-27T07:50:59+00:002.25 know that there are forces of attraction between unlike charges and forces of repulsion between like charges
Hydr0Gen2019-06-27T07:51:15+00:002.26 explain electrostatic phenomena in terms of the movement of electrons
Hydr0Gen2019-06-27T07:51:45+00:002.27 explain the potential dangers of electrostatic charges, e.g. when fuelling aircraft and tankers
Hydr0Gen2019-06-27T07:52:17+00:002.28 explain some uses of electrostatic charges, e.g. in photocopiers and inkjet printers
Hydr0Gen2022-11-29T14:56:27+00:003.01 use the following units: degree (°), hertz (Hz), metre (m), metre/second (m/s) and second (s)
Hydr0Gen2019-06-28T09:10:45+00:003.02 explain the difference between longitudinal and transverse waves
Hydr0Gen2022-11-29T14:56:50+00:003.03 know the definitions of amplitude, wavefront, frequency, wavelength and period of a wave
Hydr0Gen2022-11-29T14:57:05+00:003.04 know that waves transfer energy and information without transferring matter
Hydr0Gen2022-11-29T14:57:25+00:003.05 know and use the relationship between the speed, frequency and wavelength of a wave: v = f × λ
Hydr0Gen2019-06-28T09:12:29+00:003.06 use the relationship between frequency and time period: time period x frequency = 1 or f = 1/T
Hydr0Gen2022-11-29T14:57:37+00:003.07 use the above relationships in different contexts including sound waves and electromagnetic waves
Hydr0Gen2019-06-27T07:58:03+00:003.08 explain why there is a change in the observed frequency and wavelength of a wave when its source is moving relative to an observer, and that this is known as the Doppler effect
Hydr0Gen2022-11-29T14:58:17+00:003.10 know that light is part of a continuous electromagnetic spectrum that includes radio, microwave, infrared, visible, ultraviolet, x-ray and gamma ray radiations and that all these waves travel at the same speed in free space
Hydr0Gen2022-11-29T14:58:29+00:003.11 know the order of the electromagnetic spectrum in terms of decreasing wavelength and increasing frequency, including the colours of the visible spectrum
Hydr0Gen2022-11-29T14:58:44+00:003.12 Explain some of the uses of electromagnetic radiations, including: radio waves: broadcasting and communications, microwaves: cooking and satellite transmissions, infrared: heaters and night vision equipment, visible light: optical fibres and photography, ultraviolet: fluorescent lamps, x-rays: observing the internal structure of objects and materials, including for medical applications, gamma rays: sterilising food and medical equipment.
Hydr0Gen2022-11-29T14:58:58+00:003.13 explain the detrimental effects of excessive exposure of the human body to electromagnetic waves, including: microwaves: internal heating of body tissue, infrared: skin burns, ultraviolet: damage to surface cells and blindness, gamma rays: cancer, mutation and describe simple protective measures against the risks
Hydr0Gen2022-11-29T14:59:53+00:003.14 know that light waves are transverse waves and that they can be reflected and refracted
Hydr0Gen2022-11-29T15:00:12+00:003.15 use the law of reflection (the angle of incidence equals the angle of reflection)
Hydr0Gen2022-11-29T15:00:26+00:003.17 practical: investigate the refraction of light, using rectangular blocks, semi-circular blocks and triangular prisms
Hydr0Gen2019-06-28T09:15:46+00:003.18 know and use the relationship between refractive index, angle of incidence and angle of refraction
Hydr0Gen2019-06-28T09:16:03+00:003.19 practical: investigate the refractive index of glass, using a glass block
Hydr0Gen2022-11-29T15:00:49+00:003.20 describe the role of total internal reflection in transmitting information along optical fibres and in prisms
Hydr0Gen2019-06-28T09:17:28+00:003.22 know and use the relationship between critical angle and refractive index:
Hydr0Gen2022-11-29T15:01:34+00:003.23 know that sound waves are longitudinal waves which can be reflected and refracted
Hydr0Gen2019-06-27T08:13:11+00:003.24 know that the frequency range for human hearing is 20–20 000 Hz
Hydr0Gen2019-06-27T08:14:34+00:003.26 understand how an oscilloscope and microphone can be used to display a sound wave
Hydr0Gen2019-06-28T09:18:46+00:003.27 practical: investigate the frequency of a sound wave using an oscilloscope
Hydr0Gen2019-06-27T08:15:34+00:003.28 understand how the pitch of a sound relates to the frequency of vibration of the source
Hydr0Gen2019-06-27T08:15:57+00:003.29 understand how the loudness of a sound relates to the amplitude of vibration of the source
Hydr0Gen2022-11-29T15:03:24+00:004.01 use the following units: kilogram (kg), joule (J), metre (m), metre/second (m/s), metre/second2 (m/s2), newton (N), second (s) and watt (W)
Hydr0Gen2022-11-29T15:03:36+00:004.02 describe energy transfers involving energy stores: energy stores: chemical, kinetic, gravitational, elastic, thermal, magnetic, electrostatic, nuclear and energy transfers: mechanically, electrically, by heating, by radiation (light and sound)
Hydr0Gen2022-11-29T15:04:08+00:004.04 know and use the relationship between efficiency, useful energy output and total energy output:
Hydr0Gen2022-11-29T15:04:19+00:004.05 describe a variety of everyday and scientific devices and situations, explaining the transfer of the input energy in terms of the above relationship, including their representation by Sankey diagrams
Hydr0Gen2019-06-27T08:19:42+00:004.06 describe how thermal energy transfer may take place by conduction, convection and radiation
Hydr0Gen2019-06-27T08:20:29+00:004.08 explain how emission and absorption of radiation are related to surface and temperature
Hydr0Gen2019-06-27T08:20:52+00:004.09 practical: investigate thermal energy transfer by conduction, convection and radiation
Hydr0Gen2019-06-27T08:21:27+00:004.10 explain ways of reducing unwanted energy transfer, such as insulation
Hydr0Gen2022-11-29T15:06:49+00:004.11 know and use the relationship between work done, force and distance moved in the direction of the force: W = F × d
Hydr0Gen2022-11-29T15:12:52+00:004.13 know and use the relationship between gravitational potential energy, mass, gravitational field strength and height: GPE = m × g × h
Hydr0Gen2022-11-29T15:13:21+00:004.15 understand how conservation of energy produces a link between gravitational potential energy, kinetic energy and work
Hydr0Gen2022-11-29T15:13:32+00:004.16 describe power as the rate of transfer of energy or the rate of doing work
Hydr0Gen2022-11-29T15:13:57+00:004.17 use the relationship between power, work done (energy transferred) and time taken:
Hydr0Gen2019-06-27T10:45:36+00:004.18 describe the energy transfers involved in generating electricity using: wind, water, geothermal resources, solar heating systems, solar cells, fossil fuels, nuclear power
Hydr0Gen2019-06-27T10:45:22+00:004.19 describe the advantages and disadvantages of methods of large-scale electricity production from various renewable and non-renewable resources
Hydr0Gen2022-11-29T15:14:23+00:005.01 use the following units: degree Celsius (°C), Kelvin (K), joule (J), kilogram (kg), kilogram/metre3 (kg/m3), metre (m), metre2 (m2), metre3 (m3), metre/second (m/s), metre/second2 (m/s2), newton (N) and pascal (Pa)
Hydr0Gen2019-06-28T09:21:53+00:005.02 use the following unit: joules/kilogram degree Celsius (J/kg °C)
Hydr0Gen2019-06-27T11:19:15+00:005.03 know and use the relationship between density, mass and volume:
Hydr0Gen2019-06-27T11:20:00+00:005.04 practical: investigate density using direct measurements of mass and volume
Hydr0Gen2022-11-29T15:14:55+00:005.05 know and use the relationship between pressure, force and area:
Hydr0Gen2022-11-29T15:15:14+00:005.06 understand how the pressure at a point in a gas or liquid at rest acts equally in all directions
Hydr0Gen2019-06-27T11:21:33+00:005.07 know and use the relationship for pressure difference: p = h × ρ × g
Hydr0Gen2019-06-28T09:22:31+00:005.08 explain why heating a system will change the energy stored within the system and raise its temperature or produce changes of state
Hydr0Gen2019-06-28T09:23:05+00:005.09 describe the changes that occur when a solid melts to form a liquid, and when a liquid evaporates or boils to form a gas
Hydr0Gen2019-06-28T09:23:48+00:005.10 describe the arrangement and motion of particles in solids, liquids and gases
Hydr0Gen2019-06-28T09:24:26+00:005.11 practical: obtain a temperature–time graph to show the constant temperature during a change of state
Hydr0Gen2019-06-28T09:25:06+00:005.12 know that specific heat capacity is the energy required to change the temperature of an object by one degree Celsius per kilogram of mass (J/kg °C)
Hydr0Gen2019-06-28T09:26:27+00:005.14 practical: investigate the specific heat capacity of materials including water and some solids
Hydr0Gen2022-11-29T15:15:53+00:005.15 explain how molecules in a gas have random motion and that they exert a force and hence a pressure on the walls of a container
Hydr0Gen2022-11-29T15:16:08+00:005.16 understand why there is an absolute zero of temperature which is –273 °C
Hydr0Gen2022-11-29T15:16:24+00:005.17 describe the Kelvin scale of temperature and be able to convert between the Kelvin and Celsius scales
Hydr0Gen2022-11-29T15:16:56+00:005.18 understand why an increase in temperature results in an increase in the average speed of gas molecules
Hydr0Gen2022-11-29T15:17:15+00:005.19 know that the Kelvin temperature of a gas is proportional to the average kinetic energy of its molecules
Hydr0Gen2022-11-29T15:17:53+00:005.20 Explain, for a fixed amount of gas, the qualitative relationship between: pressure and volume at constant temperature, pressure and Kelvin temperature at constant volume.
Hydr0Gen2019-06-28T08:04:16+00:005.21 use the relationship between the pressure and Kelvin temperature of a fixed mass of gas at constant volume:
Hydr0Gen2019-06-28T08:04:40+00:005.22 use the relationship between the pressure and volume of a fixed mass of gas at constant temperature:
Hydr0Gen2019-06-28T10:53:46+00:006.02 know that magnets repel and attract other magnets and attract magnetic substances
Hydr0Gen2019-06-28T10:55:29+00:006.03 describe the properties of magnetically hard and soft materials
Hydr0Gen2019-06-28T10:45:46+00:006.05 know that magnetism is induced in some materials when they are placed in a magnetic field
Hydr0Gen2022-11-29T15:19:50+00:006.06 practical: investigate the magnetic field pattern for a permanent bar magnet and between two bar magnets
Hydr0Gen2022-11-29T15:20:00+00:006.07 describe how to use two permanent magnets to produce a uniform magnetic field pattern
Hydr0Gen2022-11-29T15:21:48+00:006.08 know that an electric current in a conductor produces a magnetic field around it
Hydr0Gen2019-06-28T10:57:31+00:006.10 draw magnetic field patterns for a straight wire, a flat circular coil and a solenoid when each is carrying a current
Hydr0Gen2019-06-28T10:49:25+00:006.11 know that there is a force on a charged particle when it moves in a magnetic field as long as its motion is not parallel to the field
Hydr0Gen2022-11-29T15:22:21+00:006.12 understand why a force is exerted on a current-carrying wire in a magnetic field, and how this effect is applied in simple d.c. electric motors and loudspeakers
Hydr0Gen2022-11-29T15:22:32+00:006.13 use the left-hand rule to predict the direction of the resulting force when a wire carries a current perpendicular to a magnetic field
Hydr0Gen2022-11-29T15:23:13+00:006.14 describe how the force on a current-carrying conductor in a magnetic field changes with the magnitude and direction of the field and current
Hydr0Gen2019-06-28T10:58:17+00:006.15 know that a voltage is induced in a conductor or a coil when it moves through a magnetic field or when a magnetic field changes through it and describe the factors that affect the size of the induced voltage
Hydr0Gen2019-06-28T10:58:44+00:006.16 describe the generation of electricity by the rotation of a magnet within a coil of wire and of a coil of wire within a magnetic field, and describe the factors that affect the size of the induced voltage
Hydr0Gen2019-06-28T10:59:11+00:006.17 describe the structure of a transformer, and understand that a transformer changes the size of an alternating voltage by having different numbers of turns on the input and output sides
Hydr0Gen2019-06-28T10:59:38+00:006.18 explain the use of step-up and step-down transformers in the large-scale generation and transmission of electrical energy
Hydr0Gen2019-06-28T11:00:11+00:006.19 know and use the relationship between input (primary) and output (secondary) voltages and the turns ratio for a transformer:
Hydr0Gen2019-06-28T11:01:23+00:006.20 know and use the relationship: input power = output power V_p I_p=V_s I_p for 100% efficiency
Hydr0Gen2022-11-29T15:23:30+00:007.01 use the following units: becquerel (Bq), centimetre (cm), hour (h), minute (min) and second (s)
Hydr0Gen2022-11-29T15:24:49+00:007.02 describe the structure of an atom in terms of protons, neutrons and electrons and use symbols such as 146C to describe particular nuclei
Hydr0Gen2022-11-29T15:24:58+00:007.03 know the terms atomic (proton) number, mass (nucleon) number and isotope
Hydr0Gen2022-11-29T15:41:02+00:007.04 know that alpha (α) particles, beta (β−) particles, and gamma (γ) rays are ionising radiations emitted from unstable nuclei in a random process
Hydr0Gen2022-11-29T15:41:27+00:007.05 describe the nature of alpha (α) particles, beta (β−) particles, and gamma (γ) rays, and recall that they may be distinguished in terms of penetrating power and ability to ionise
Hydr0Gen2022-11-29T15:41:48+00:007.06 practical: investigate the penetration powers of different types of radiation using either radioactive sources or simulations
Hydr0Gen2019-06-28T08:11:55+00:007.07 describe the effects on the atomic and mass numbers of a nucleus of the emission of each of the four main types of radiation (alpha, beta, gamma and neutron radiation)
Hydr0Gen2019-06-28T08:12:23+00:007.08 understand how to balance nuclear equations in terms of mass and charge
Hydr0Gen2019-06-28T08:12:47+00:007.09 know that photographic film or a Geiger−Müller detector can detect ionising radiations
Hydr0Gen2022-11-29T15:42:15+00:007.10 explain the sources of background (ionising) radiation from Earth and space
Hydr0Gen2019-06-28T08:13:38+00:007.11 know that the activity of a radioactive source decreases over a period of time and is measured in becquerels
Hydr0Gen2022-11-29T15:42:34+00:007.12 know the definition of the term half-life and understand that it is different for different radioactive isotopes
Hydr0Gen2019-06-28T08:14:23+00:007.13 use the concept of the half-life to carry out simple calculations on activity, including graphical methods
Hydr0Gen2022-11-29T15:43:06+00:007.16 describe the dangers of ionising radiations, including: that radiation can cause mutations in living organisms, that radiation can damage cells and tissue, the problems arising from the disposal of radioactive waste and how the associated risks can be reduced.
Hydr0Gen2022-11-29T15:43:29+00:007.17 know that nuclear reactions, including fission, fusion and radioactive decay, can be a source of energy
Hydr0Gen2022-11-29T15:43:41+00:007.18 understand how a nucleus of U-235 can be split (the process of fission) by collision with a neutron, and that this process releases energy as kinetic energy of the fission products
Hydr0Gen2022-11-29T15:43:54+00:007.19 know that the fission of U-235 produces two radioactive daughter nuclei and a small number of neutrons
Hydr0Gen2019-06-28T09:29:30+00:007.20 describe how a chain reaction can be set up if the neutrons produced by one fission strike other U-235 nuclei
Hydr0Gen2019-06-28T09:30:07+00:007.21 describe the role played by the control rods and moderator in the fission process
Hydr0Gen2019-06-28T09:31:49+00:007.23 explain the difference between nuclear fusion and nuclear fission
Hydr0Gen2019-06-28T09:32:18+00:007.24 describe nuclear fusion as the creation of larger nuclei resulting in a loss of mass from smaller nuclei, accompanied by a release of energy
Hydr0Gen2019-06-28T09:35:10+00:007.26 explain why nuclear fusion does not happen at low temperatures and pressures, due to electrostatic repulsion of protons
Hydr0Gen2022-11-29T15:48:25+00:008.01 use the following units: kilogram (kg), metre (m), metre/second (m/s), metre/second2 (m/s2), newton (N), second (s), newton/kilogram (N/kg)
Hydr0Gen2019-06-28T10:26:08+00:008.02 know that: the universe is a large collection of billions of galaxies, a galaxy is a large collection of billions of stars, our solar system is in the Milky Way galaxy
Hydr0Gen2019-06-28T10:33:35+00:008.03 understand why gravitational field strength, g, varies and know that it is different on other planets and the Moon from that on the Earth
Hydr0Gen2019-06-28T10:34:02+00:008.04 explain that gravitational force: causes moons to orbit planets, causes the planets to orbit the Sun, causes artificial satellites to orbit the Earth, causes comets to orbit the Sun
Hydr0Gen2019-06-28T10:36:11+00:008.05 describe the differences in the orbits of comets, moons and planets
Hydr0Gen2019-06-28T10:36:32+00:008.06 use the relationship between orbital speed, orbital radius and time period:
Hydr0Gen2019-06-28T10:37:05+00:008.07 understand how stars can be classified according to their colour
Hydr0Gen2019-06-28T10:37:27+00:008.08 know that a star’s colour is related to its surface temperature
Hydr0Gen2019-06-28T10:37:45+00:008.09 describe the evolution of stars of similar mass to the Sun through the following stages: nebula, star (main sequence) , red giant, white dwarf
Hydr0Gen2019-06-28T10:38:13+00:008.10 describe the evolution of stars with a mass larger than the Sun
Hydr0Gen2019-06-28T10:13:43+00:008.11 understand how the brightness of a star at a standard distance can be represented using absolute magnitude
Hydr0Gen2019-06-28T10:14:24+00:008.12 draw the main components of the Hertzsprung–Russell diagram (HR diagram)
Hydr0Gen2019-06-28T10:14:50+00:008.13 describe the past evolution of the universe and the main arguments in favour of the Big Bang
Hydr0Gen2019-06-28T10:15:21+00:008.14 describe evidence that supports the Big Bang theory (red-shift and cosmic microwave background (CMB) radiation)
Hydr0Gen2019-06-28T10:15:53+00:008.15 describe that if a wave source is moving relative to an observer there will be a change in the observed frequency and wavelength
Hydr0Gen2019-06-28T10:16:50+00:008.16 use the equation relating change in wavelength, wavelength, velocity of a galaxy and the speed of light:
Hydr0Gen2019-06-28T10:17:24+00:008.17 describe the red-shift in light received from galaxies at different distances away from the Earth
Hydr0Gen2019-06-28T10:17:58+00:008.18 explain why the red-shift of galaxies provides evidence for the expansion of the universe