Physics paper 1 p1-7 Flashcards
Define energy
The ability for something to do work.
Define conservation of energy
Can’t be created or destroyed. It can transfer between stores.
Give the unit of energy
Joules (J).
Name the 7 different energy stores
Chemical, gravitational, kinetic, nuclear, thermal, electromagnetic, elastic
Identify which store of energy is associated with objects raised above the earth’s surface
Gravitational.
Identify which store of energy is associated with hot objects
Thermal.
Identify which store of energy is associated with moving objects
Kinetic.
Identify which store of energy is associated with objects that have been stretched
Elastic.
Identify which store of energy is associated with the nucleus of an atom
Nuclear.
Identify which store of energy is associated with the energy stored in bonds between atoms
Chemical.
Identify which store of energy is associated with charged or magnetised objects
Electromagnetic.
Give the equation for calculating weight
Weight = mass x gravity
Give the equation for calculating work done
Work done = force x distance
Give the equation for calculating Kinetic Energy
Kinetic energy = 0.5 x mass x speed²
Give the equation for calculating Gravitational Potential Energy
Gravitational potential energy = mass x gravity x change in height
Give the equation for calculating force applied to a spring
Force applied = spring constant x extension
Give the equation for calculating efficiency of energy or power
Efficiency = useful output (energy or power) / total input (energy or power)
Define efficiency
A measure of the useful energy transferred by an object compared to the total amount of energy it uses.
Describe how the efficiency of a machine can be improved
Lubricate moving parts to reduce friction. Secure all screws to reduce vibrations. Use streamline shapes.
Give the equations for calculating power
Power = work done / time; Power = energy transferred / time
Define power
The amount of energy transferred by an object each second.
Give the unit of power
Watts (W).
Define thermal conductivity
The ability of a material to transfer energy by heating.
Define a conductor
A material with a high thermal conductivity (it’s good at transferring heat).
Define an insulator
A material with a low thermal conductivity (it’s bad at transferring heat).
Define conduction
The transfer of energy through a material by the vibration of its atoms.
Define convection
The circulation of a fluid caused by increasing its thermal energy.
Define specific heat capacity
The amount of energy needed to raise the temperature of a 1kg substance by 1 °C.
Describe how loft insulation reduces heat loss
Made from fiberglass which has a low thermal conductivity. The material is mainly air
Describe how cavity wall insulation reduces heat loss
Made from insulating foam. Contains air pockets to stop conduction.
Describe how double glazing reduces heat loss
Vacuum between two panes of glass. Reduces conduction and convection.
Describe how aluminium foil behind a radiator reduces heat loss
Shiny surface reflects heat back into the room.
Give factors that affect how quickly a substance heats up
Mass, thermal energy applied, specific heat capacity
Define fuels
Substances that release energy when burned.
Define fossil fuels
Fuels made from dead animals and plants. Non renewable.
Define biofuel
Fuels made directly from plant material. Renewable.
Describe what is meant by ‘carbon neutral’
Total amount of carbon dioxide emitted during combustion is balanced by the amount absorbed during growth.
Define renewable
It is replaced at the rate it is being used.
List the different forms of renewable energy
Biofuels, solar, wind, wave, tidal, hydroelectric, geothermal
Give the advantages of using energy from renewable sources
No greenhouse gases. They won’t run out. Less maintenance.
Give the disadvantages of using energy from renewable sources
Expensive, unreliable, generates less energy than fossil fuels.
Give the advantages of solar power
Free once built, no pollution.
Give the disadvantages of solar power
Expensive, doesn’t work at night.
Give the advantages of hydroelectric power
No waste,water can be stored and used to generate power.
Give the disadvantages of hydroelectric power
Dams destroy environment, affects water quality
Give the advantages of wind power
No fuel needed, area underneath can be used for farming
Give the disadvantages of wind power
Noisy,unsightly
Give the advantages of biomass
Cheap,recycles waste, carbon neutral
Give the disadvantages of biomass
Greenhouse gases released.
Give the advantages of geothermal power
Power stations are small,no pollution
Give the disadvantages of geothermal power
Can only be built in specific locations
Give the advantages of nuclear power
High energy output, powerstation has high lifespan
Give the disadvantages of nuclear power
Radioactive waste
Describe how a power station works
Fuels are burnt to release steam. Steam turns a turbine. Generator makes electricity. Transformer sets correct voltage.
Define electrical current
Flow of charge from positive to negative terminal of a battery.
Describe what an electrical current is made up of
Moving electrons.
Give the unit for current
Amps (A).
Describe how we measure current
With an ammeter
Define potential difference
Work done between two points in a circuit.
Give the unit for potential difference
Volts (V).
Describe how we measure potential difference
With a voltmeter
Define resistance
Materials that oppose the flow of current.
Give the unit for resistance
Ohms (Ω).
List factors that affect resistance
Length and thickness of wires. Number of components. Temperature and type (series/parallel) of circuit. Materials.
Describe what happens to the resistance as a wire gets longer
Resistance increases.
Define a series circuit
All components connected in the same loop. Current has one path to flow in.
Give the current/potential difference/resistance characteristics of a series circuit
Current = same everywhere. Potential difference = shared between components. Total resistance = sum of resistances added.
Define a parallel circuit
Components can be set up in different loops. The current has more than one path to flow in.
Give the current/potential difference/resistance characteristics of a parallel circuit
Total current = sum of currents through each branch. Potential difference = same across each branch. Resistance = decreases as you add more resistors in parallel.
Describe how to calculate potential difference (V)
Potential difference = current x resistance. V = IR
Give the equation that links power
current and potential difference
Give the equation that links power
current and resistance
Give the equation that links energy transferred
charge flow and potential difference
Define alternating current
An electric current that repeatedly changes direction.
Define direct current
An electric current that flows in one direction.
Define power
Rate of energy transfer (P= E/t). Measured in Watts.
Name and explain the role of the blue wire in a cable
Neutral wire. Carries a 0V potential difference. Completes the circuit.
Name and explain the role of the brown wire in a cable
Live wire. Carries the 230V alternating potential difference.
Name and explain the role of the green & yellow wire in a cable
Earth wire. Safety feature that prevents electric shocks.
List the three equations for calculating power
Power = Energy / time
Power = Current x potential difference
Power = Current² x resistance
Define ‘national grid’
Network of cables and transformers connecting electricity producers to users.
Explain what a step up transformer does
Increases potential difference. Reduces current. Stops cables getting hot. Reduces wasted energy. Increases efficiency.
Explain what a step down transformer does
Decreases potential difference. Increases current. Makes it safe to be used in houses by appliances.
Give the UK mains electricity frequency and potential difference
Alternating current; Frequency = 50Hz; Potential difference = 230V
List the properties of solids
Fixed shape fixed volume, cannot be compressed, particles arranged in rows, particles vibrate in fixed positions
List the properties of liquids
Change shape,fixed volume, cannot be compressed, particles arranged randomly but still touching, particles can slide past each other.
List the properties of gases
Change shape,change volume, can be compressed, particles arranged randomly and spaced far apart, particles move freely in all directions.
Give the name of the process that changes a solid to a liquid
Melting.
Give the name of the process that changes a liquid to a gas
Boiling.
Give the name of the process that changes a gas to a liquid
Condensing.
Give the name of the process that changes a liquid to a solid
Freezing.
State what happens to the temperature during a change in state
Stays the same.
Define density
Amount of mass per unit of volume.
Give the formula for calculating density
Mass / volume
Give the name of the piece of equipment would you use to measure the volume of an irregularly shaped object
Eureka can.
Define internal energy
Total kinetic and potential energy of all particles in a system.
Define latent heat
Energy needed to change state.
Define latent heat of fusion
Energy needed to melt 1kg of solid.
Define latent heat of vaporisation
Energy needed to boil 1kg of liquid.
Give the formula for calculating latent heat
Energy = mass x latent heat
Describe what causes air pressure on a surface
Particles colliding with walls of a container.
List 3 ways the pressure of a gas be increased
Reducing container size (volume); Increasing temperature; Increasing particle concentration.
List the three types of radiation
Alpha; Beta; Gamma.
Give the properties of alpha radiation
Helium nucleus,positively charged, most ionising, least penetrating, most dangerous at short distances, stopped by paper.
Give the properties of beta radiation
High energy electron,negatively charged, medium ionisation and penetration, most dangerous at mid distances, stopped by aluminium.
Give the properties of gamma radiation
Electromagnetic wave,no charge, least ionising, most penetrating, most dangerous at long distances, stopped by concrete.
Define background radiation
Low levels of radiation that are around us all the time.
List the natural sources of background radiation
Radon gas; Cosmic rays; Food and drink; Grounds and buildings.
List the man-made sources of background radiation
Medical x-rays; Nuclear power; Nuclear weapons.
Describe the plum pudding model of the atom
Mass evenly distributed. Positive charge spread throughout the atom. Electrons embedded randomly. Atom is solid.
State who conducted the gold foil experiment
Ernest Rutherford.
Describe 3 things that were observed during the gold foil experiment
Alpha particles went straight through; Some deflected; Some bounced back.
Give 3 conclusions which resulted from the gold foil experiment
Atoms are mostly empty space; Small central region of positive charge; Most of the mass is in this central region.
State what the gold foil experiment proved
Existence of the nucleus.
Describe the nuclear model of the atom
Mass concentrated in the nucleus; Positive charge in the nucleus only; Electrons orbit in shells; Mostly empty space.
Define half life
The time taken for radiation levels to decrease by 50%.
