Transverse and Longitudinal Waves

What do waves do?

Waves transfer energy from one place to another without transferring matter

Explain how waves transfer energy (how they travel from one place to another)


When waves travel through a medium (material), the particles of the medium oscillate and transfer energy between each other - the particles stay in the same place, only energy is transferred

What happens when waves travel from one place to another?


They oscillate

On a displacement-distance wave graph, what is the displacement? (what does it mean?)


The displacement is how far from the equilibrium (the middle line) the wave has oscillated (gone up or down)

On a displacement-distance wave graph, what is the amplitude? (what does it mean?)


The maximum displacement

On a displacement-distance wave graph, what is the trough?


The lowest point (the very bottom) of an oscillation

On a displacement-distance wave graph, what is the crest? 


The peak (the highest point) of an oscillation

On a displacement-distance wave graph, what is the wavelength?


The distance of one entire oscillation (it has to start from one point on a wave and end at the same point on the next wave e.g. crest to crest)

On a displacement-distance wave graph, what is the distance? (what does it mean?)



How far the wave has travelled from its starting point

On a displacement-time wave graph, what is the time period? (what does it mean?)



The time it takes for one complete oscillation

The time period on a displacement-time graph is represented the same way as something else on a displacement-distance graph, what is this something?


Wavelength (time period and wavelength both measure one complete oscillation)

What is the formula for working out frequency when using a distance-time graph? (referring to frequency and time-period)


F=1/T

frequency (Hz) = 1 / time period (s)

What is the equation for wave speed (speed of a wave)? (including units of measurements)

Wave speed (m/s) = Frequency (Hz) x Wavelength (m)

What is frequency measured in?


Hertz (Hz)

What is wave speed measured in?


m/s

What is the difference between transverse and longitudinal waves?


• Oscillations in a transverse are perpendicular to the direction of energy transfer (direction the wave is moving) - so the vibrations go up and down

• Oscillations in a longitudinal wave are parallel to the direction of energy transfer (this means that some regions are more spread out than others) - so the waves are vibrating back and forth)

Most waves we can think of are transverse, give examples of the main ones.


• All electromagnetic waves

• Ripples and waves in water

• Waves in strings (guitar)

Give an example of a type of longitudinal wave.


Sound waves