the energy of waves section 1: the nature of waves
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The Energy of WavesThe Energy of Waves
Section 1: The Nature of WavesSection 1: The Nature of Waves
Anticipation Guide: True or Anticipation Guide: True or FalseFalse
Light waves are mechanical waves Light waves are mechanical waves because they must travel in a mediumbecause they must travel in a medium
In space, no one can hear an explosionIn space, no one can hear an explosion
Water waves are a combination of Water waves are a combination of longitudinal and transverse waveslongitudinal and transverse waves
What is a wave?What is a wave?
Definition: A wave is any disturbance that Definition: A wave is any disturbance that transmits energy through matter or space.transmits energy through matter or space.
Waves carry energy, not Waves carry energy, not mattermatter
Waves use energy to do work on everything in its path. The waves do work on the water to make it move up and down as well as work on the leaf so it bobs up and down with the water.
Energy transfer through a Energy transfer through a mediummedium
a wave can be described as a disturbance a wave can be described as a disturbance that travels through a medium, that travels through a medium, transporting energy from one location to transporting energy from one location to another location. another location.
The medium is simply the material through The medium is simply the material through which the disturbance is moving; it can be which the disturbance is moving; it can be thought of as a series of interacting thought of as a series of interacting particles. particles.
Mechanical wavesMechanical waves require a medium require a medium
Sound waves require a mediumSound waves require a medium Ocean waves require a mediumOcean waves require a medium Waves on a string instrument require a Waves on a string instrument require a
mediummedium
A A mechanical wavemechanical wave is a wave which is is a wave which is not capable of transmitting its energy not capable of transmitting its energy through a vacuum. In other words, it through a vacuum. In other words, it requires a mediumrequires a medium
An example of a mechanical An example of a mechanical wavewave
Energy transfer without a Energy transfer without a mediummedium
Electromagnetic waves are waves that do Electromagnetic waves are waves that do not require a medium to transmit energynot require a medium to transmit energy
Examples of these are microwaves, TV, x-Examples of these are microwaves, TV, x-rays, and radio signals rays, and radio signals
While these types of waves can travel While these types of waves can travel through a medium, they travel faster through a medium, they travel faster through empty spacethrough empty space
Example of an electromagnetic Example of an electromagnetic wavewave
Waves in the electromagnetic spectrum vary in size from very long radio waves the size of buildings, to very short gamma-rays smaller than the size of the nucleus of an atom.
Types of WavesTypes of Waves
Waves can be classified based on the Waves can be classified based on the direction that the particles of the medium direction that the particles of the medium vibrate compared to the direction in which vibrate compared to the direction in which the waves travel.the waves travel.
The two main types of these waves are The two main types of these waves are transverse and longitudinal. If found in transverse and longitudinal. If found in combination is called a surface wave.combination is called a surface wave.
Types of Waves: TransverseTypes of Waves: Transverse
Transverse waves have particles that Transverse waves have particles that vibrate in an up and down motion moving vibrate in an up and down motion moving the waves across in a perpendicular the waves across in a perpendicular manner to which the wave is travelingmanner to which the wave is traveling
Remember that perpendicular means to Remember that perpendicular means to be at right anglesbe at right angles
A rope is an example of a transverse A rope is an example of a transverse wave. wave.
Types of Waves: TransverseTypes of Waves: Transverse
Types of Waves: TransverseTypes of Waves: Transverse
Demonstration
Types of Waves: LongitudinalTypes of Waves: Longitudinal
A longitudinal wave has particles that A longitudinal wave has particles that vibrate back and forth along the same path vibrate back and forth along the same path that the wave travels.that the wave travels.
A spring (or slinky) is an example of a A spring (or slinky) is an example of a longitudinal wavelongitudinal wave
Types of Waves: LongitudinalTypes of Waves: Longitudinal
Compression is when the spring is Compression is when the spring is (particles are) tightly pushed together(particles are) tightly pushed together
Refraction is when the coils (particles) are Refraction is when the coils (particles) are spread farther apart.spread farther apart.
A sound wave is an example.A sound wave is an example.
Types of Waves: LongitudinalTypes of Waves: Longitudinal
Demonstration
Types of Waves: CombinationTypes of Waves: Combination
When waves occur at or near the When waves occur at or near the boundary between two media (air and boundary between two media (air and water for example) transverse wave and a water for example) transverse wave and a longitudinal wave can combine to form a longitudinal wave can combine to form a surface wave.surface wave.
Surface waves look like transverse waves Surface waves look like transverse waves but the particles in the medium move in but the particles in the medium move in circles rather than up and down.circles rather than up and down.
Types of Waves: CombinationTypes of Waves: Combination
Particles move forward at the crest and backward in the trough.
Anticipation Guide: Anticipation Guide: True or FalseTrue or False
Light waves are mechanical waves Light waves are mechanical waves because they must travel in a mediumbecause they must travel in a medium
In space, no one can hear an explosionIn space, no one can hear an explosion
Water waves are a combination of Water waves are a combination of longitudinal and transverse waveslongitudinal and transverse waves
False
True
True
Xelectromagnetic
Sound waves require a medium
Also called surface waves.
