Unit 4 - Waves Flashcards
What is a wave?
A wave is something that transfers energy from one point to another, often requiring particles to vibrate.
What are the two main types of waves?
Transverse waves and Longitudinal waves
How do particles move in a transverse wave?
They vibrate at right angles to the direction the energy travels.
How do particles move in a longitudinal wave?
They vibrate in the same direction as the energy travels.
What type of wave is a water wave?
A transverse wave
What type of wave is a sound wave?
A longitudinal wave
What is the symbol and unit for wavelength?
λ (lambda), measured in metres (m)
What is frequency?
The number of waves produced per second by a source, measured in Hertz (Hz)
What is the symbol for frequency?
f
Define amplitude.
Half the distance from peak to trough; the height of the wave from the rest position.
What is wave speed?
A measure of how quickly the wave travels from its source; measured in m/s
What is the formula for wave speed?
v = f × λ
What is the symbol for wave speed?
v
What is the unit for wave speed?
Metres per second (ms⁻¹)
Define period (T).
Time taken for one complete wave to pass a point; measured in seconds.
What is the relationship between period and frequency?
T = 1 ÷ f or f = 1 ÷ T
What is the formula for frequency when number of waves and time are known?
f = n ÷ t
How do you calculate speed when distance and time are known?
v = d ÷ t
In the equation v = d ÷ t, what do the letters represent?
v = speed, d = distance, t = time
What is the speed of sound in air?
340 ms⁻¹
What is the speed of light (and all EM waves) in a vacuum?
3 × 10⁸ ms⁻¹
What is diffraction?
The spreading out of waves when they pass through a gap or past an edge.
When is diffraction most noticeable?
When the gap width is similar to the wavelength.
True or False: The wavelength of a wave changes after diffraction.
False — the wavelength remains unchanged.
