Chapter 14 Notes- Waves

Section 1- Types of Waves

What is a Wave?

-A ______is a periodic disturbance in a solid, liquid, or gas as ______is transmitted through a medium.

-Waves carry energy through ______or ______.

-Most waves travel through a ______.

  • The matter through which a wave travels is called the medium.

-Waves that require a medium are called ______waves.

-______does not require a medium.

  • Light waves consist of changing ______and ______fields in space.

-Light waves are called ______waves.

-An electromagnetic wave consists of oscillating electric and magnetic fields, which radiate outward at the ______.

-Waves transfer ______.

-Energy may spread out as a wave travels.

  • When sound waves travel in air, the waves spread out in ______. As they travel outward, the spherical wave fronts get bigger, so the energy in the waves spreads out over a larger area.

Vibrations and Waves

-Waves are related to ______.

-Most waves are caused by a vibrating object.

  • Electromagnetic waves may be caused by vibrating charged particles.
  • In a ______wave, the particles in the ______also vibrate as the wave passes through the medium.

-Vibrations involve transformations of ______.

Transverse and Longitudinal Waves

-Particles in a medium can vibrate either ______or ______.

-Waves are often classified by the ______that the particles in the medium move as a wave passes by.

-______waves have ______motion.

-A ______wave is a wave in which the particles of the medium move perpendicular to the direction the wave is traveling.

  • ______waves are transverse waves.

-Longitudinal waves have ______motion.

-A ______wave is a wave in which the particles of the medium vibrate parallel to the direction of the wave ______.

  • ______waves are longitudinal waves.

-In a surface wave, particles move in ______.

  • Surfaces waves occur at the ______between two different mediums, such as between water and air.
  • The particles move ______perpendicularly and parallel to the direction that the wave travels.

Section 2- Characteristics of Waves

Wave Properties

Transverse Wave

-______measures the amount of particle vibration.

  • The ______is the highest point of a transverse

wave.

  • The ______is the lowest point of a transverse

wave.

  • The ______is the maximum distance that the particles of a wave’s medium vibrate from their ______position.

Longitudinal Wave

-A longitudinal wave has compressions and rarefactions.

  • The crowded areas are called ______.
  • The stretched-out areas are called ______.
  • The ______of a longitudinal wave is the

maximum deviation from the normal density or

pressure of the medium.

-______measures the distance between two equivalent

partsof a wave.

  • The wavelength is the distance from any point on a wave to an ______point on the next wave.
  • Not all waves have a single wavelength that is easy to measure.
  • Wavelength is represented by the Greek letter lambda, ______.

-The ______measures how long it takes for waves to pass by.

  • The period is the time that it takes a ______cycle or wave oscillation to occur.
  • The period is represented by the symbol T.

-______measures the rate of vibrations.

  • The frequency is the number of cycles or ______per unit of ______.

Wave Speed

Part of Equation / Symbol / Units

Formulas:

Math Skills: The string of a piano that produces the note middle C vibrates with a frequency of 264Hz. If the sound waves produced by this string have a wavelength in air of 1.30m, what is the speed of sound in air?

What we know:f =

=

What we want to know:s =

Equation:s =

Substitution:s =

Final answer with unitss =

-The speed of a wave depends on the ______.

  • In a given medium, though, the speed of waves is ______; it does not depend on the frequency of a wave.

-______theory explains differences in wave speed.

  • The ______of particles in a medium determines how well waves travel through it.
  • In ______, the molecules are far apart and move around randomly. Waves ______travel as fast in gases.
  • In ______, such as water, the molecules are much closer together. But they are also free to slide past one another.
  • In a ______, molecules are not only closer together, but also tightly bound to each other. Waves travel ______through most solids.

-______has a finite speed.

  • All electromagnetic waves in empty space travel at the same speed, the speed of light, which is 3.00 x 108 m/s (______).
  • Light travels ______when it has to pass through a medium such as air or water.

Doppler Effect

-______is determined by the frequency of sound waves.

  • The pitch of a sound, how ______or ______it is, is determined by the frequency at which sound waves strike the eardrum in your ear.
  • A higher-pitched sound is caused by sound waves at ______frequency.

-Frequency changes when the ______of waves is moving.

  • The ______is an observed change in the frequency of a wave when the source or ______is moving.

Section 3- Wave Interactions

Reflection, Diffraction, and Refraction

-______is the bouncing back of a ______of light, sound, or heat when the ray hits a surface that it does not go through.

-Waves reflect at a ______boundary.

  • The reflected wave is exactly like the original wave except that the reflected wave is traveling in the ______direction to the direction of the original wave.

-At a ______boundary, waves reflect and turn ______.

-______is the ______of waves around an edge.

  • Diffraction is a change in the ______of a wave when the wave finds an obstacle or an edge, such as an opening.

-Waves can also bend by ______.

  • Refraction is the ______of a wavefront as the wavefront passes between two substances in which the speed of the wave differs.
  • All waves are refracted when the pass from one medium to another at an ______.

Interference

-Waves in the same place ______to produce a single wave.

  • Interference is the combination of two or more waves of the ______frequency that results in a ______wave.
  • The resulting wave can be found by ______the height of the waves at each point.
  • Crests are considered ______, and troughs are considered ______.

-Constructive interference ______amplitude.

  • Constructive interference is any interference in which waves combine so that the resulting wave is ______than the original waves.
  • The ______of the resulting wave is the sum of the amplitudes of the two individual waves.

-Destructive interference ______amplitude.

  • Destructive interference is any interference in which waves combine so that the resulting wave is ______than the largest of the original waves.
  • When destructive interference occurs between two waves that have the same amplitude, the waves may completely ______each other out.