Waves

• What are the two types of waves? [2] - Transverse - Longitudinal
• What do all waves transfer from one place to another? Energy
• What does oscillate mean? Vibrate
• What do particles that make a wave oscillate about? A fixed point
• What happens afterwards when the particles that make up a wave oscillate about a fixed point? They pass the energy on to the next particles, which also oscillate and so on
• Does the matter remain the same, as energy moves along? Yes
• In a transverse wave, at what direction are the oscillations to the energy transfer? Perpendicular (right-angle)
• In a longitudinal wave, at what direction are the oscillations to the energy transfer? Parallel
• What do all wave have? [4] - Frequency - Amplitude - Wavelength - Period
• What is the frequency of a wave? The number of waves passing a fixed point per second,
• What is the frequency of a wave measured in? Hertz
• What is the amplitude of a wave? The maximum displacement that any particle achieves from its undisturbed position in metres (m)
• What is the wavelength of the wave? The distance from point on a wave to the equivalant point on the next wave in metres (m)
• What is the period of a wave? The time taken for one complete oscillation in seconds (s)
• What happens when you are observing waves? [2] - Amplitude is seen as the wave height - Period is the time taken for one complete wave to pass a fixed point
• What does the amplitude indicate? The amount of energy a wave is carrying - the more energy, the higher the amplitude
• What is the speed of a wave? The speed at which energy is transferred
• What is the equation for wavespeed? Wavespeed = frequency x wavelength Wavespeed = metres per second Frequency = Hertz Wavelength = Metres
• What is a mechanical wave? A wave that requires a medium (substance) to travel through.
• What type of waves are electromagnetic waves/ Transverse waves
• What do electromagnetic wave travel through? [2] - Medium - Vacuum
• What does the electromagnetic spectrium from from, and then to? From low frequency, low energy waves to high frequency, high energy waves.
• What are human eyes only capable of detecting? Visible light
• What does does the wavelength of an electromagnetic wave affect? How it's absorbed, transmitted, reflected or refracted by different substances. This affects its uses
• What can happen to a wave when it passes from one medium to another? It can be refracted and change direction
• What does the direction of refraction depend on? [2] - The angle at which the wave hits the boundary - The materials involved
• What is refractive index? For light rays, that shows the way in which a material affects refraction
• What happens when light travels from a material with a low refractive index to one with a higher refractive index? It bends towards the normal
• What happens when light travels from a material with a high refractive index to one with a lower refractive index? It bends away from the normal
• What is a refraction due to? Due to the difference in the wave speed in the different medium
• When a light wave enters, at an angle, a medium in which it travels: What happens to the first part of the light wave entering the medium? It slows down
• What happens to the rest of the wave after the first part of the light wave enters the medium slows dow? The rest of the wave continues at higher speeds
• As the rest of the wave continues at higher speeds what does this cause the wave to do? Causes the wave to change direction, towards the normal
• What can happen when waves reach a boundary between one medium and another? They can be refracted
• What can ray diagrams be used to show? What happens when a wave reaches a boundary of one medium and another
• What should you do when constructing a ray diagram? [4] "- Rays must be drawn with a ruler - Each straight section of ray should have a single arrow drawn on it to indicate the direction of movement - Where the ray meets the boundary, a ""normal"" should be drawn at right-angles to the boundary - All relevant angles should be labelled"
• When are ray diagrams used? Whenever a diagram is needed to represent how light moves from one place to another
• What are radio waves used for? [3] - Television - Radio - Bluetooth
• What are radio waves? [2] Low energy waves This makes them not harmful, making them ideal for radio transmission
• What are the uses of microwaves? [2] - Satellite communications - Cooking food