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| Question | Answer |
| What are Waves? | Waves transfer energy from one point to another without transferring matter. they consist of disturbances which transfer the energy in the direction of the wave, without moving the matter. |
| Name the types of waves: | - Transverse waves - Longitudinal waves |
| What are Transverse waves? | In a transverse wave, each particle moves up and down or side to side. These vibrations are at right angles to the direction of the wave. |
| Example of a transverse wave: | Water waves and light waves. Water waves can be observed in a ripple tank. |
| Why does a rubber duck placed in water only move up and down whilst the energy move along the tank? | Because the water only moves up and down (at right angles) to the direction of the wave. |
| How is energy passed along the water? | Energy is passed along the water from one wave to another. |
| In a transverse wave what is a high part/peak called? | crests |
| What are low parts in a transverse wave called? | troughs |
| what is a wavelength in a transverse wave? | the distance between two successive crests or two successive troughs. |
| what is the amplitude of a transverse wave? | the height of the crest from undisturbed surface or the depth of a trough from an undisturbed surface. |
| what are longitudinal waves? | In a longitudinal wave the particles vibrate forwards and backwards. The vibrations are parallel to the direction of the wave. |
| Name an example of a longitudinal wave: | Sound waves |
| How is sound energy transferred? | Sound energy is transferred from one molecule to another and so travel along the wave. |
| what are compressions? | Compressions are the regions where the molecules are close together and have a higher particle density. has a higher pressure. |
| what are rarefactions? | Rarefactions are regions where the molecules are further apart and have a lower particle density. has a lower pressure. |
| what is the wavelength in a longitudinal wave? | the wavelength is the distance between successive compressions or the distance between successive rarefactions. |
| amplitude in a longitudinal wave? | the amplitude is the maximum distance the vibrating particle travels from its undisturbed distance. |
| What is the frequency of a wave? | the frequency of a wave is a measure of the number of waves made by a source each second or the number of waves that pass through a particular point each second. |
| what is frequency measured in? | measured in a unit called Hertz (Hz) which is the number of wave cycles per second. |
| the wave equation and what does each letter stand for? | v = wave speed f = frequency λ = wavelength |
| using the triangle how do you work out the wave speed? | v = f x λ |
| how do you work out the frequency? | f = v / λ |
| how do you work out the wavelength? | λ = v / f |
| what is wave speed, frequency and wavelength measured in? | wave speed = m/s frequency = Hz wavelength = m |
| when waves go from one medium to another what might happen? | Reflection - the light can bounce back (e.g. light striking a mirror) Refraction - the wave can change speed and direction Absorption - the wave can give up its energy (e.g. microwaves are absorbed by food in a microwave oven) |
| what is the electromagnetic spectrum order? | 1) radio waves 2) microwaves 3) infra red radiation 4) visible light 5) ultra violet 6) x rays 7) gamma rays |
| what is reflection? | the waves bounce back |
| an example of reflection: | light waves striking a mirror or echoes in which sound waves are reflected off a solid surface. |
| what is the law of reflection? | angle of incidence = angle of reflection |
| what angle id the normal? | 90 degrees (right angle) |
| using the diagram, how does a periscope work? | a periscope works by the light waves hitting mirror A and then being reflected off an the exact same angle, it then travels down and hits mirror B where it is reflected again at the exact same angle to the person eye. |
| what changes the speed of a wave? | wave speed changes depending upon the medium which is travels along or through. |
| as well as speed what else changes as it moves from one medium to another? | the change in wavelength and direction. |
| what is the change of direction or bending of the wave called as it passes from one medium to another? | refraction. |
| the speed of a wave is affected by ... | the medium in which the wave is travelling |
| a change in wave speed causes a change in ... | wavelength as frequency cannot change |
| the normal line is an imaginary construction line ... | at a right angle to the refracting or reflecting surface at the point of incidence. |
| what happens when light travels into a denser medium? | when light travels into a denser medium the waves are refracted towards the normal and on leaving the denser medium are refracted away from the medium. |
| why? | because light travels slower in a denser medium. |
| what happen when sound travels into a denser medium? | when sound travels into a denser medium the waves are refracted away from the normal and on leaving the denser medium are refracted towards the medium. |
| why? | because sound waves travel faster in a denser medium. |
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