Waves Flashcards
Waves
Waves transfer energy from one location to another, without transferring matter.
Formed from disturbances
For a wave to be created, there is an initial disturbance or vibration. This disturbance sends energy via the wave, away from its source in every direction. A disturbance can be a single impulse, or a series of impulses or continuous.
Moving energy with or without a medium
Energy can be transferred via waves with or without the use of a medium. If waves use matter to transfer energy, they are referred to as mechanical waves. If waves do not require a medium to transfer they are electromagnetic waves.
Mechanical Waves
Waves that require a movement of energy are referred to as mechanical waves. They cause a temporary disturbance in the medium, but the medium has no displacement.
Oscillation of Particles
Mechanical Waves can carry energy over significant distances. However the particles that make up the medium have a limited range of movement. The particles are restricted to back and forth motion, and is referred to as oscillations.
Transverse Waves
A transverse wave is a wave form that sees the individual vibrations within the wave moving perpendicular to the direction of wave motion. For mechanical transverse waves, the particles are parallel to the wave direction. They take the shape of sine and cosine curves.
Comparing transverse and longitudinal waves
Transverse waves can transmit energy in the form of mechanical and electromagnetic waves, whereas longitudinal waves can only transmit energy through a mechanical wave.
Examples of waves
Sound waves are a key example of longitudinal waves. As sound travels through a medium, the partices within that medium oscillate back and forth. When particles move from their relaxed state to a more dense area, a compression arises. When particles moved from their relaxed state to a less dense area, a rarefraction arises.
Properties of Transverse Waves
Transverse waves see particles displaced from the equilibrium position. The equilibrium position represents the undisturbed, rest position of the particles. When representing a transverse wave equilibrium is drawn as a horizontal line in the middle of the wave.
Crest and Trough
The crest of a transverse wave is the highest point of the wave. If considering displacement, the crest would be the point furtherest from the equilibrium position in the +ve direction. The trough of a transverse wave is at the lowest point of a wave.
Amplitude and Wavelength
The amplitude of a transverse wave is measured by the displacement or height from the equilibrium position to maximum position. The wavelength is the length of one complete cycle of a wave ON DISPLACEMENT VS POSITION.
Period
Time taken to complete one cycle ON DISPLACEMENT VS TIME GRAPH.
Properties of a transverse wave
The frequency is the measure of how many cycles occur in one second. Easily confused with the period, the frequency is the reciprocal of the period.
- First measure period using f = 1/T. Frequency and period are inversely proportional
Properties of a transverse wave
The frequency is the measure of how many cycles occur in one second. Easily confused with the period, the frequency is the reciprocal of the period.
- First measure period using f = 1/T. Frequency and period are inversely proportional
Compression and Rarefraction
Longitudinal waves disturb particles away from their equilibrium positions to form regions of high density or low density. The areas of high density are known as compressions and the areas of low density are rarefractions.
