Karteikarten
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- 1PHYSICS 1PHYSICS
1 - 2What happens to particles when a substance is heated?When a substance is heated,its particles gain kinetic energy.
- 3What is the formula for wavespeed?Wavespeed=Frequency x Wavelength
- 4Draw and label a wavelength with the wavelength,amplitude,crest and trough.
- 5Dylan is standing on the end of a pier.He measures the water waves going past hi.The wavelength of each wave is 1.3m.He counts 2 waves every second.Find the wave speed.wavespeed=Frequency x wavelength
f =2hz (as there are 2 waves every second)
v = 2 x 1.3
v = 2.6m/s - 6A flute produces a note with a wavelength of 75cm.The speed of sound is 330m/s.Find the frequency of the note.Wavespeed = frequency x wavelength
Frequency = wavespeed divided by wavelength
f = 330/0.75
f = 440 hz - 7What is a wavelength,frequency and a amplitudeWavelength- Distance from one crest of a wave to the next crest
Frequency- The number of oscillations per second for a vibration
Amplitude- Maximum height of the wave measured from the middle. - 8What are some of the uses of lasers?Some uses are:
> Surgery and dental treatments
> guiding weapons
> CD,DVD and Blu-Ray players
> Cutting materials such as plates - 9What is a laser?A laser is a very narrow beam of light that travels long distances.
- 10How is a CD read by a laser?There are billions of pits on the average CD.This digital information is read by the laser.As the disc spins,a laser reflects from its surface.When the light enters a pit there is no reflection,and so the detector reads a series of light pulses.
- 11What is efficiency?Efficiency is a percentage of how much useful energy is produced by the input energy.
- 12What is conduction?Conduction is the transfer of energy through solids.When the particles in a solid are hotter,they have more energy so vibrate more.When you heat one end of an object,the particles start vibrating more.The particles collide with other particles,kinetic energy is transferred from one particle to its neighbours.
- 13What is convection?Convection is the transfer of energy through liquids and gases.
- 14What is radiation?Energy transfered by radiation is infrared radiation and is the transfer of energy by electromagnetic waves.
- 15How does the surface of an object affect how much radiation it will absorb?Objects can absorb radiation from the sun.The surface of an object effects how much energy it absorbs.A dark matt surface is good at absorbing infrared radiation.A light coloured or shiny surface is bad at absorbing infrared radiation.
- 16What order does the seven electromagnetic waves go?Radiowaves
Microwaves
Infrared
Visable Light
Ultra Violet
X-Rays
Gamma Rays - 17what does the electromagnetic spectrum show you?The electromagnetic spectrum shows you that when the wavelength increases the frequency increases.
- 18What is diffraction and Refraction?Diffraction- spreding out of waves when they pass through a gap or around an obstacle
Refraction- Change of speed and direction of a wave when it passes from one medium to another. - 19What does the law of reflection state?The raw of reflection states that the angle of incidence is equal to the angle of reflection.
- 20When does total internal reflection happen?Toal internal reflection hppens if the angle is above the critical angle for the material.
- 21What are fibre optics?Fibre optics are very fine glass cables,they can be used to transmit large amounts of information or to help doctors with surgery.Waves travel along optic fibre by total internal reflection.They reflect off the inside of the glass fibre untill they reach the other end.
- 22What is a conductor,a thermogram,a insulator,temperature and heat?Conductor- Material that allows energy to pass through it.
Thermogram- A special camera which is sensitive to infrared radiation but not visable light.
Insulator- Material that does not allow energy to pass through.
Temperature- A measure of how hot or cold an object is.
Heat- A form of energy measured in joules. - 23How do you calculate pay back time?Payback Time = cost/ savings per year
- 24What are an analogue and digital signal?An analougue signal can take any value within a certain range.The amplitude and frequency of an analogue wave vary continuously.
A digital signal can only take two values.These values tend to be on/off or 1/0.For example,you can send data along optical fibres as short pulses of light, - 25What does UV do to your skin?The more time you spend in the sun,the more chance you have of getting skin cancer.This is because the suns rays include UV which damages the DNA in your cells.
- 26Ruvani normally burns after 40 minites in the sun.Before going to the beach,she applies sunscreen with SPF 8.For how long can she sunbathe before she will start to burn?Time = 40mins x 8 = 320 mins = 5 hours and 20 mins
- 27What is happening to the ozone layer?The ozone layer absorbs some of the UV rays from the sun- so it reduces the amount of Uv reaching the earths surface.Recently,the ozone layer has been getting thinner because of pollution from CFCs- these gases which react with the ozone molecules and break them up.
- 28What are p-waves?>P-waves are longitudinal.
>Longitudinal waves-the vibrations are along the direction that the wave travel.
>The waves travel left and right.P-waves travel through solids and liquids.
>They travel faster then s-waves
>The p-waves pass through the core and are detected at the crust - 29What are s-waves?>S-waves are transverse
>The vibrations are at right angles to the direction that the wave travels
>S-waves only travel through solids
>They are slower than P-Waves.
>No s waves travel through the core so are not detected at the crust.
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- GCSE Science (science exam) Karteikarten am Ohne Titel, erstellt von angel915 am 09/05/2014.
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- angel915
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