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70 Cards in this Set
- Front
- Back
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Frequency |
The number of waves passing a point each second, measured in Hertz |
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Speed |
Measured in metres per second. distance ÷ time |
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Wavelength |
The distance between a point on one wave and the same point on the next Wave |
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Time |
The time taken for one wavelength to pass a point. Period = 1/frequency |
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Examples of Longitudinal waves |
Sound waves seismic p waves |
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How does sound waves work |
Particles in the material the sound of travelling through move back and forth along the same direction at the sound is travelling. Particles in a longitudinal wave always move along the same direction as the wave. |
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Examples of transverse waves |
Waves on water surface, electromagnetic waves, seismic S waves and light rays |
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How to transverse waves work |
The particles move in the direction at right angles to the direction the wave is travelling. Particles in a transverse wave move across the direction the wave is travelling. |
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Equation for wave speed |
Frequency x wavelength |
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Which waves can refraction happen to |
Sound waves water waves light waves |
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What is refraction |
Change of both speed and direction as a wave enters a substance of a different material |
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What happens to a sound wave when it goes through a material with a similar density |
It is transmitted |
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What happens to a sound wave if there is a large difference in the density of the material at interface |
It is reflected |
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Uses of radio waves |
Radio and television |
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Uses of microwaves |
Microwaves for cooking food and satellite communication |
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Uses for infrared |
Electrical heaters, cooking food and infrared cameras |
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Uses of visible light |
Fibre optic Communications |
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Uses of ultraviolet light |
Energy efficient lamps and sun tanning |
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Uses of X-rays |
Medical imaging and treatment |
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Uses of gamma rays |
Medical imaging and treatment |
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Which end of the em spectrum has the highest wavelength |
Radio waves |
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Which end of the em spectrum has the highest frequency |
Gamma rays |
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Which end of the em spectrum has the lowest frequency |
Radio waves |
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Which end of the em spectrum has the shortest wavelength |
gamma rays |
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What are the most dangerous parts of the em spectrum and why |
Ultraviolet, x-rays and gamma rays as due to their short wavelength and high frequency they can be ionising |
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What is the danger of infrared radiation |
Skin Burns |
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What is the danger of X-rays and gamma rays |
Can kill cells and cause mutations which can lead to cancer |
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What is the danger of ultraviolet light |
Can cause eye damage, sunburn and skin cancer |
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How does the ear detect sound |
Sound waves are channelled in the ear canal and cause the eardrum to vibrate. These vibrations pass through the ear further vibrations are then converted into an electrical signal and carried to the brain |
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What are sound waves |
A series of oscillations that transfer energy from the source to the ear due to the vibrations of the object/source |
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Uses of infrasound |
Communication between animals such as elephants and whales, detecting volcanic eruptions and detecting meteor strikes |
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Uses of ultrasound |
Making images of the inside of the body such as prenatal scans as well as sonar. Also the breaking up of kidney stones |
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State the law of reflection |
Angle of incidence = angle of reflection |
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What happens when the angle of incidence = critical angle |
Refracted light passes along the boundary of the glass block |
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When does total internal reflection happen |
When light travelling through a dense material (like glass) meets the boundary with a less dense material, (such as air) light speeds up and changes Direction away from the normal. Above the critical angle the light is totally internally reflected. |
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Define amplitude |
The maximum displacement from the point of equilibrium |
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Danger of microwaves |
Internal heating of body cells |
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What is the eardrum |
A Thin membrane |
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What happens inside the cochlea |
Vibrations are passed on to the liquid inside the cochlea then the tiny hairs inside the cochlea detect these vibrations and create electrical signals called impulses which travel along the auditory nerve to the brain. |
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What is the purpose of the tiny bones in the ear |
They amplify the vibrations |
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What happens when the angle of incidence is greater than critical angle |
The light is completely reflected inside the Block and total internal reflection occur |
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Define a real image |
An image formed when light rays from an object converge and meet each other and can be projected onto a screen |
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Give an example of a real image |
Images formed on a cinema screen |
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Define virtual image |
The image that's formed when light rays from an object do not meet but appear to meet behind the lens and cannot be projected on a screen. Formed by the divergence of light away from a point and always appear up right |
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Give an example of a virtual image |
Image formed of a person's reflection in a mirror |
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What is specular reflection |
When parallel waves are reflected from a surface |
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What is diffuse reflection |
This occurs when the surface is not smooth and has rough irregularities, the wave is then a reflected at many angles and the reflected rays will not be parallel |
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Define CMB radiation |
Cosmic microwave background radiation received from all over the sky originating at the Big Bang |
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What is the steady state Theory |
The idea that the Universe has always existed and is expanding. New matter is continuously created as it expands so it always look the same |
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What is The Big Bang Theory |
The idea that the whole universe started as a hot dense point of energy about 14 billion years ago. Since then it has expanded and cooled into the current universe. Gravity has pulled together matter to form stars and galaxies. |
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Which Theory is redshift evidence for |
Both |
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Which Theory does the discovery of CMB radiation in support of |
The Big Bang Theory as the big bang would have produced a large amount of electromagnetic radiation early in the formation of the Universe which has been red shifted into the microwave part of the electromagnetic spectrum |
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Define acceleration |
The rate of change of velocity |
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How is acceleration calculated |
Displacement ÷ time |
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How is acceleration calculated on a velocity time graph |
It is calculated by finding the gradient of the line |
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How is distance calculated on a velocity time graph |
By calculating the area underneath the line |
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Name some vectors |
Velocity and displacement |
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Name some scalars |
Speed and distance |
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What's the difference between a scalar and a vector |
A scalar is a quantity that has a magnitude size. Vectors are scalars that also have Direction |
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Define speed |
The rate of change of distance |
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How is speed found on a displacement time graph |
By calculating the gradient of the line |
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Define activity |
The no. Of radioactive nuclei that decay per unit time |
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Define half life |
Time taken for no. Of radioactive nuclei to half |
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How is radon gas formed |
Uranium in rocks decays into radon gas in the air (this is ionising) |
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Name some background radiation |
Gamma radiation emitted from stars Medical purposes Nuclear power stations |
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Define irradiation |
Exposing objects to Nuclear radiation. Does not make them radioactive |
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Define contamination |
Presence of radioactive substances inside the body of an object. |
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Define nuclear fission |
An unstable parent nucleus splits into two or more daughter nuclei and several neutrons |
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Define nuclear fusion |
Two nuclei release fusion as they are fused together to form one larger nucleus |
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Force in momentum |
Change in momentum ÷ time |
