| what is a wave | something that transfers energy from one point to another |
| what are the two types of waves | transverse
longitudinal |
| what is a transverse wave | waves in which the direction of travel of energy is at right angles to the oscillation of the particles
for instance, water waves |
| what type of waves are all of the waves in the EM Spectrum | transverse |
| what is a longitudinal wave | waves in which the direction of travel of energy is along the same direction as the oscillation of the particles
for instance, sound waves |
| what is meant by wavelength | the distance from one position on a wave to the corresponding position on the next wave
eg crest to crest or trough to trough |
| what is the symbol for wavelength | λ - lambda
wavelength is measured in metres |
| what is meant by frequency | the number of waves which pass a point in one second. Measured in Hertz (Hz) and is given the symbol 'f' |
| What is meant by amplitude | the peak value of a waveshape; it is measured from the central line to the crest of the wave
it can also be thought of the height of the wave from rest position -- in the middle when the wave is not moving up or down
it is measured in metres and is given the letter 'a' |
| what is wave speed | a measure of how quickly the waves travels from its source.
Its value is the same as the distance covered by a wave in one second
it is measured in metres per second and is given the symbol 'v' |
| what is meant by period | the time taken for one complete wave to be produced
also known as the time taken for one wave to pass a point
it is measured in seconds and has the symbol 'T' |
| what is the crest of a wave | the topmost part of a wave shape |
| what is the trough of a wave | the lowest part of a wave shape |
| what is the formula/relationship between frequency and period of a wave | T=1/f
Period=1/frequency
OR
f=1/T
frequency=1/period |
| what is the formula for frequency when given a number of waves and a time | f=N/t |
| what is the formula for speed | v=d/t |
| describe an experiment for measuring the speed of sound waves | set up two microphones connected to an electronic timer
use a metre stick to set two microphones 1m apart
at one microphone make a loud sharp noise
when the sound reaches the first microphone the timer starts. When the sound reaches the 2nd microphone the timer stops. The timer will display the time taken
Use v=d/t to calculate speed |
| what is the speed of sound in air | 340ms-1 |
| what is the formula for wave speed? | v=fλ
where wave speed is measured in ms-1
frequency in Hertz
wavelength in metres |
| what is the speed of light | 3x10^8ms-1 |
| what is meant by diffraction | the property of a wave in which the wave is bent around an obstacle or through a gap |
| what factors affect extent of diffraction? | width of the gap compared to the waves wavelength
wavelength of the wave |
| how does width of the gap affect diffraction | a narrow gap causes a lot of diffraction to occur
(gap width less than the wave's wavelength)
a wide gap causes little diffraction
(gap width greater than the wavelength) |
| how does wavelength affect diffraction | the greater the wavelength of a wave, the greater the diffraction that occurs |
