Karteikarten
Physics 1
Karten in diesem Stapel (55)
- 1What does energy do in the form of heat?it flows from a warmer to a colder body
- 2What does a thermogram show?temperature by colour- hottest area = yellow and white
coldest areas = blue and purple - 3What happens when body temp increases?the average kinetic energy of the particles increases
- 4What is specific heat capacity?the energy needed to raise the temp of 1kg by 1 degree celcuis
measured in joules - 5What happens when an object is heated and its temperature rises?energy is transferred
- 6What is specific latent heat?the energy needed to melt or boil 1kg of a material
- 7What happned when an object changes state?energy is transferred but the temp remains constant
- 8What happens when a substance changes state?energy is needed t break the bonds that hold the molecules together.
- 9Double glazing:reduces energy loss by conduction-gap between the glass is filled with air or argon or has a vacuum, no particles in them so impossible to transfer energy.
- 10Loft insuation:reduces energy loss by conduction and convection
- 11Cavity wall:insulation reduces energy loss by conduction and convection- air in foam= good insulator so air cannot move by convection as its trapped
- 12Insulation blocks:reduces energy by transfer of radiation- energy form sun is reflected back to keep home cool and vis versa from home to sun
- 13What is conduction due to ?transfer of kinetic energy between particels
- 14What is convection due to ?a gas expands when heated makes it less dense so it rises
- 15What is radiation due to ?does not need a material to trandsfer energy trasferred through a vacuum
- 16What is the amplitude of a wave?maximum displacement of a particle from its rest position
- 17What is the crest?is the highest point on a wave above its rest position
- 18what is a trough?lowest point of a wave
- 19What is a wavelength?a wave is the distance between two successive points on a wave having the same displacement and moving in the same direction
- 20What is the frequency of a wave?the number of complete waves passing a point in 1sec
- 21Why does refraction occur?because the speed of waves decreases as the wave eneters a more dense medium and increases as the wave enters a less dense medium
- 22What is diffraction?the spreading out of a wave as it passes through a gap- the amount depends on the size of a gap= larger gap is less diffraction
- 23What is morse code?a series of dots and dashes to represent alphabet- digital signal
- 24What is instantanousa signal sent by light, electricity, microwaves or radio
- 25What is white light?made up of differnent colours of different frequencies out of phase
- 26How many frequency's does laser light have?1 is in phase and shows low divergence
- 27What is a endoscope?it allows doctors to see inside a body without the need for surgery
- 28Light passes from a more dense to a ...less dense martial- angle of refraction is larger than angle of incidence
- 29when a angle of refraction is 90 degress the angle of incidence is called the ?critical angle
- 30What is total internal refraction?when the angle of incidence is bigger than the critical angle
- 31How is data transmitted?along critical angles
- 32how much does infrared radiation penertrate food?does not penertrate it very easily
- 33how many cm does microwaves penetrate?up to 1cm into the food
- 34How is energy transferred?by waves- the amount of energy depends on the frequency or wavelength of the wave, high freq=short freq
- 35How do normal ovens cook?by infrared radiation- energy is absorbed by the surface of the food, the kinetic energy on the surface increases, rest of oven heated by conduction
- 36what is microwave radiation used for?to communicate over long distances
- 37What does infrared allow?carries information that allows electronic and electrical devices to be controlled
- 38What do optical fibres allow?data to be transmitted very quickly using pulses of light
- 39What happens before an anologue signal is transmitted?it is added to a carier wave- freq is usually high, interference form another wave can be added and transmitted meaning if the wave is amplified so is the interferrnce
- 40What is multiplexingwhere it allows a large number of digital signals to be transmitted at the same time.
- 41What happens to radio waves in the earth's atmosphere?they are reflected and refracted- the amount of refraction depends on the frequency of the wave, less refraction at higher frequencies.
- 42how is interference reduced?if digital signals are used- DAB eliminates interfernce between radio stations
- 43Where are radio waves refracted?the ionosphere- behave like light and undergo total internal refraction
- 44What happens to microwaves at the ionosphere?they pass through- they are recived by orbiting satellites, amplified and retrasmitted bad to earth
- 45When are radio waves diffracted?when they meet an obstruction
- 46What are p waves?longitudinal pressure waves
- 47What are s waves?transverse waves
- 48What are l waveswaves that travel round the surface very slowly
- 49How do p waves travelthey travel through the earth- they are refracted at the core
- 50How do s waves work?they are not detected on the opposite side of the Earth- they will not travel through liquid
- 51What causes a tan?UV light on the skin- cells in the skin produce melanin a pigment that produces tan
- 52How are risks reduced?by wearing sunscreen
- 53where is the ozone found?stratosphere
- 54What does the ozone do?it helps to filter out UV radiation
- 55What destroys the ozone?CFC's
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- Karteikarten am Physics 1, erstellt von frenchfry99 am 19/03/2015.
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- frenchfry99 · Mär 2015
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- 19 Feb 2016
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