Gcse AQA physics Questions and Answers 2022/2023

Gcse AQA physics Questions and Answers 2022/2023 how is heat transferred from place to place? conduction, convection, radiation What surface is better at absorbing heat? dark matt surfaces what surface is better at reflecting heat? light shiny surfaces what objects emit infared radiation? all objects. the hotter it is, the more it emits. what does infared radiation involve? waves! not particles what can radition pass through? vaccum particles in solids, liquids and gases have ? amounts of energy different describe the particles in a solid close together particles, with a regular pattern.They vibrate and stay in a fixed position describe the particles in a liquid close particles with a random patter. Move around eachother describe the particles in a gas far apart, random pattern, move quickly and in any direction what is conduction when heat energy moves through a substance are metals, or non metals better conductors metals what are non metals and gases good insulators the hotter the metal is... the more kinetic energy the vibrations have what happens in convection particles with lots of heat energy get less dense and rise, replacing particles with less heat energy. what is it called when a liquid changes to a gas? evaporation what is it called when a gas changes to a liquid condensation what increases condensation rate? increase in temperature of gas what increases rate of evaporation? increase in temperature of liquid, increase surface area, air moving over liquids surface the bigger difference in temperature between object and surroundings... the greater rate of heat energy is transferred small animals have large surface area to volume ratio if small animals have a large surface area to volume ratio they lose heat to surroundings easily and have to eat more to replace energy lost large animals have a small surface area to volume ratio if large animals have a small surface area to volume ratio they lose little heat to surroundings and may risk over heating what enables elephants to cool down quickly large ears lower u-value means better heat insulator what does temperature mean measure of how hot an object is what does heat mean measure of thermal energy contained temperature increase depends on mass of an object, substance it is made from, amount of energy transferred to the obect what are forms of energy magnetic, kinetic, heat, light, gravitational potential, electrical, elastic potential, nuclear what diagram shows the useful and wasted energy sankey diagram what are fossil fuels coal, oil, natural gas what are advantages of fossil fuels they are reliable and quick what are disadvantages of fossil fuels supply is limited, coal and oil release sulphur dioxide, release carbondioxide when burned, increases global warming, what releases the most carbon dioxide, coal or natural gases? coal example of a nuclear fuel uranium, plutonium advantages of nuclear fuels? dont produce sulphur dioxide or carbon dioxide disadvantages of nuclear fuels? non renewable, radioactive material released if there is an accident which would damage health what is wind energy? wind blows into wind turbines, causing them to turn and drive a generator what are the types of water energy? wave, tides, hydroelectric power what is wave energy kinetic energy in waves drive electricity generators what is tide energy tidal barrage is built over a river to make use of kinetic energy in moving water. barrage contains electricity generators which are driven by water rushing through tubes in the barrage what is hydroelectric power? moving water drives electrical generators which are built inside dams advantages of water power? no fuel costs, no harmful gases, reliable, easily switched on disadvantages of water power? hard to produce large amounts of electricity, tidal barrages destroy habitats, hydroelectricity floods farmland, rotting vegetation under water releases methane, a greenhouse gas what is geothermal energy? hot water and steam underground is used to drive turbines how does geothermal energy work in volcanic areas? rocks contain radioactive substances, rocks heat water so it rises to surface naturally, steam and hot water drives turbines and electricity generators how does geotheraml energy work in hot rocks? hot water and steam doesnt rise to the surface, deep wells drilled down to hot rocks and cold water is pumped down to condense the water, hot water rises and can be used to drive turbines and electricity generators advantages of solar energy? renewable, provides energy in remote locations disadvantages of solar energy? inefficient, doesnt work at night how is electricity distributed from power stations to consumers? the national grid what does a step up transformer do steps up voltage what does a step down transformer do decreases the voltage how do you work out the speed of a wave frequency plus wavelength what is a transverse wave? where the vibrations (oscillations) are at right angles to the direction of travel what speed does light travel at, through a vaccum? the same speed what is a longitudinal wave? oscillations are along the same direction as travel what is amplitude the maximum disturbance from undisturbed position what is wavelength length from one chord (bump) to the other what is frequency number of waves produced by a source each second what happens to sound and light waves when they cross a boundary with different densities, e.g air and glass they change speed and change direction what is diffraction when waves meet gap in barrier and they carry on through but more spread out if the gap in diffraction is larger than the wavelength what happens it doesnt spread very much and causes a sharp shadow what happens in diffraction if the gap is similar to the wavelength it causes a lot of spreading with little shadow what waves reflect from surfaces sound and light waves where is the angle of incidence between the incident (incoming ray) and the normal where is the angle of reflection between the reflected ray and the normal what type of echo does a smooth surface produce when a sound wave hits it? strong echo where can waves appear to be coming from? a point beyond the mirror the angle of incidence is the same as the... angle of reflection are sound waves longitudinal or transverse? longitudinal what direction do vibrations occur in? same direction as travel the greater the amplitude of an object... the louder the sound the greater frequency of an object... the higher the pitch what does an object / substance produce when it vibrates? sound what is the electromagnetic spectrum? white light split into prism to form a spectrum what speed do all forms of electromagnetic radiation travel at? the same speed when was the big bang thought to have happened? 13.7 billion years ago what is the big bang theory? origin in all matter of universe was concentrated to a single tiny point and then expanded rapidly into a huge explosion what is the dopplar effect? when a source travels towards you the wavelength decreases and the frequency increases, when a source travels away from you the wavelength increases and the frequency decreases what happens to the source in the dopplar effect when it moves away from you the wavelength increases and the frequency decreases what direction are distant galaxies moving from us? away from us the further away a galaxy is... the faster it is moving what does CMBR mean? microwaves coming from every direction in space