Wave

• any disturbance that transmits energy through matter or empty space.
• most transfer energy by the vibration of particles in a medium.

Medium

• a substance through which a wave can travel

Mechanical Waves

• waves that need a medium
• examples:sound waves, water waves, and seismic waves

Electromagnetic Waves

• waves that can transfer energy without giving through a medium
• examples: visible light waves, microwaves, radio waves, and x rays

Transverse Waves

• waves in which the particles vibrate perpendicularly to the direction the wave is traveling
• highest part:crest
• lowest part:trough
• examples: water waves, waves on a rope, electromagnetic waves

Longtitudinal Waves

• waves in which the particles vibrate back and forth along the path that the wave moves.
• made up of compression -where particles are crowded together- and rarefractions- where particles are spread out
• examples: waves on a spring, sound waves

Surface Waves

• forms when a transverse wave and longitudinal wave combine
• look like transverse waves but particles of the medium move in circles rather than up and down

Amplitude

• the maximum distance that the particles of a medium vibrate from their rest position
• related to the height of the wave
• wave w/ large amplitude caries more energy than wave w/ small amplitude
• larger amplitude, taller the wave

Wavelength

• the distance between any point on a wave to an identical point on the next wave
• distance between two troughs or rarefractions together
• wave w/ shorter wavelength carries more energy than wave w/ longer wavelengh does
• wavelength (λ)= wavespeed (v)/ frequency (f)

Frequency

• the number of waves produced in a given amount of time
• expressed in hertz(Hz)- 1 hertz= 1 wave per second
• high-frequency waves carry more energy than low-frequency waves when the amplitudes are equal
• frequency (f)=wave speed (v)/ wavelength (λ)

Wave Speed

• speed at which the wave travels
• wave speed (v)= wavelength (λ) x frequency (f)

Christiaan Huygens

• 1629-1695
• Dutch mathematician, astronomer, physicist
• life overlapped Galileo and Sir Isaac Newton
• invented pendulum clock and developed the first wave theory- any point on a wave can be a source of a new disturbance

Reflection

• happens when aa wave bounces back after hitting a barrier
• all waves -including water, sound, and light waves- can be reflected

Refraction

• the bending of a wave as the wave passes from one medium to another at an angle
• when a wave moves from one medium to another, the wave's speed and length change

Diffraction

• the bending of waves around a barrier or through an opening
• the amount of diffraction of a wave depends on its wavelength and the size of the barrier or opening the wave encounters

Interference

• the result of 2 waves overlapping
• when 2 or more waves share the same space, they overlap.

Constructive Interference

• happens when the crest of the wave overlaps the crest of another wave or waves. Troughs also overlap.

Destructive Interference

Standing Wave

• waves that appear to be standing still.
• only looks as if its standing still. It's actually going in both directions.

Reasonant Frequencies

• the frequencies at which standing waves are made.

Reasonance

• happens when an object vibrating at or near the reasonant frequency of a second object causes the second object to vibrate.
• the reasonating object absorbs energy from the vibrating object and vibrates.