3. Waves Flashcards
What is a progressive wave?
A progressive (moving) wave carries energy from one place to another without transferring any material.
Define a wave.
A wave is the oscillation of particles or fields.
How can you tell electromagnetic waves carry energy.
They cause things to heat up. X rays and gamma rays knock electrons out of the orbit (ionisation).
Define wave cycle.
One complete vibration of the wave.
Define displacement (in terms of waves).
How far a point on the wave has moved from the equilibrium position. Measured in metres.
Define amplitude and state it’s units.
Maximum magnitude of displacement. Measured in metres.
Define wavelength.
The length of one whole wave cycle, from crest to crest or trough to trough. Measured in metres.
What is a period and what is it’s units?
The time taken for a whole cycle to complete or pass a given point. Measured in seconds.
Define frequency and state it’s units?
The number of cycles per second passing a given point. Measured in hertz.
Define phase.
A measurement of the position of a certain point along the wave cycle.
What is the phase difference?
The amount one wave lags behind another.
What is phase and phase difference measured in?
Angles (degrees or radians) or as fraction of a cycle.
