Waves Flashcards
What are waves?
Transfer energy from one place to another without transferring matter
Longitudinal or transverse
What happens in water and air?
It is the wave not the substance that moves
An object dropped on water causes ripples but neither the object nor water moves with the ripples
When you speak, the voice box vibrates, making sound waves travel through air. The air itself does not travel away from your throat
What do mechanical waves need?
A medium to travel through, causing the particles in the substance to oscillate and pass energy on to neighbouring partciles
What are transverse waves?
The oscillations of a transverse wave are perpendicular to the direction in which the waves transfer energy
E.g ripples on the surface of the water
What are longitudinal waves?
The oscillations are parallel to the wave direction
Cause areas of rarefaction and compression
E.g sound waves
Amplitude
Maximum displacement of a point on a wave from its undisturbed position (m)
Frequency
Number of waves passing a fixed point per second
Period
Time taken for one complete wave to pass a fixed point
Wavelength
Distance from one point on a wave to the equivalent point on the next wave
Wave speed
Distance travelled by each wave per second and the speed at which energy is transferred by the wave (m/s)
How do you calculate period?
1/ frequency
What happens when waves travel from one medium to another?
Speed and wavelength may change but frequency stays the same
What is speed?
Distance/ time
What happens when a wave arrives at the boundary between two diffrent substances?
Absorption
Reflection
Refraction
Transmission
Absorption
The energy of waves is transferred to the energy stores of the substance they travel in
