Waves, light & sound notes
Waves
A wave is a disturbance that carries energy from one place to another. There are 2 main groups of waves and 3 types of waves.
Two groups:
Mechanical- need some type of medium (what they move through) to exist. Examples: sound, water waves...
Electromagnetic (EM)- can move without a medium. Examples: any of the EM waves (light, microwaves, TV, radio...).
Three types:
Transverse- the medium moves perpendicular to the direction the wave travels. Example: tie a rope to a tree/ flick the rope to make an up-down wave- note: the rope moves up and down but the wave in the rope travels along the rope (perpendicular to the up-down motion). EM waves are transverse waves.
Longitudinal- the medium moves parallel to the wave motion/ the medium & wave move in the same direction. Example: stretch a slinky/ take one end and QUICKLY pull it out some more and push it back to where it was. If you do this right the slinky stays in a straight line but you notice that wave in the coils moving to the other end and back. Sound waves are an example of this type of wave.
Surface- a wave that is a combination of the other two types.
Wave parts:
Crest- top of wave/ Trough- bottom of wave/ Amplitude- height of wave/ Wavelength- distance between two side-by-side crests or troughs.
A wave is a disturbance that carries energy from one place to another. There are 2 main groups of waves and 3 types of waves.
Two groups:
Mechanical- need some type of medium (what they move through) to exist. Examples: sound, water waves...
Electromagnetic (EM)- can move without a medium. Examples: any of the EM waves (light, microwaves, TV, radio...).
Three types:
Transverse- the medium moves perpendicular to the direction the wave travels. Example: tie a rope to a tree/ flick the rope to make an up-down wave- note: the rope moves up and down but the wave in the rope travels along the rope (perpendicular to the up-down motion). EM waves are transverse waves.
Longitudinal- the medium moves parallel to the wave motion/ the medium & wave move in the same direction. Example: stretch a slinky/ take one end and QUICKLY pull it out some more and push it back to where it was. If you do this right the slinky stays in a straight line but you notice that wave in the coils moving to the other end and back. Sound waves are an example of this type of wave.
Surface- a wave that is a combination of the other two types.
Wave parts:
Crest- top of wave/ Trough- bottom of wave/ Amplitude- height of wave/ Wavelength- distance between two side-by-side crests or troughs.
Frequency is the number of waves per second. The line drawn down the middle is called normal and shows seconds for frequency problems.
problem
Which wave below has the greatest amount of energy? Which wave has the greatest frequency?
problem
Which wave below has the greatest amount of energy? Which wave has the greatest frequency?
Light
Light is a transverse wave and an electromagnetic wave. It has 4 properties: reflection, refraction, diffraction and interference.
Reflection- the bouncing of light off of a surface. Typically you think of mirrors with reflection (and that's true) but any surface (besides black surfaces) reflect light.
Three are 3 type of mirrors.
Light is a transverse wave and an electromagnetic wave. It has 4 properties: reflection, refraction, diffraction and interference.
Reflection- the bouncing of light off of a surface. Typically you think of mirrors with reflection (and that's true) but any surface (besides black surfaces) reflect light.
Three are 3 type of mirrors.