P1.5 - Waves Flashcards
What do waves transfer and what DON’T they transfer?
Waves transfer energy without transferring matter.
What is the amplitude of a wave?
The amplitude of a wave is the distance from the rest position of a wave to the crest, or the top of the wave.
What is the amount of energy that a wave has dependent on?
The amount of energy a wave has depends on its amplitude.
What is meant by the wavelength of a wave?
The wavelength (λ) is the length of a “full cycle” of a wave, so from crest to crest.
What is the frequency of a wave?
The frequency is the number of complete waves produced by a source per second or the number of complete waves passing a point per second.
What is frequency measured in?
Frequency is measured in hertz (Hz).
1 Hertz is what?
1Hz is 1 wave per second.
How are transverse waves formed?
Transverse waves are formed by vertical vibrations (oscillations) from side to side.
What are some examples of transverse waves?
Light waves
Heat waves
Electromagnetic waves
Water ripples
Waves on strings
What are the properties of the oscillations of transverse waves?
In a transverse wave, the oscillations/vibrations are perpendicular (at 90 degrees) to the direction of energy transfer of the wave.
What are the sections of a longitudinal wave?
Longitudinal waves have compressions and rarefactions.
How do the particles in a longitudinal wave move?
The particles move backwards and forwards in the direction that the wave is travelling.
How do you work out the wavelength of a longitudinal wave?
The wavelength of a longitudinal wave is the distance between two compressions or two rarefactions.
What are some examples of longitudinal waves?
Sound waves
Ultrasound
P-Waves (seismic waves)
What are the properties of the oscillations of longitudinal waves?
In a longitudinal wave, the oscillations/vibrations are parallel to the direction of energy transfer of the wave.
What is the wave equation?
Speed (M/S) = Frequency (Hz) * Wavelength (M)
What is the speed of a wave independent of?
The speed is usually independent of the frequency or amplitude of the wave.
All waves can be…
All waves can be reflected, refracted, and diffracted, for when waves arrive at an obstacle their direction of travel will change.
When will the reflection of light be at different angles?
The reflection of light will be at different angles when light hits an uneven surface.
When will the reflection of light be at the same angle?
The reflection of light will be at the the same angle when light hits an even surface (like a mirror).
What is the “normal line”?
The “normal line” is an imaginary line that is perpendicular to the surface where light hits the surface (the point of incidence).
The angle of incidence is equal to what?
The angle of incidence = the angle of reflection.
What is a plane mirror?
A plane mirror is simply a flat mirror.
What are the properties of a reflected image?
The image is virtual - the image cannot be projected onto a screen (it is behind the mirror).
It is the same size as the original object.
It is upright.
The image is as far behind the mirror as the object is in front.
It is laterally inverted - the left and right sides are swapped.