Key Idea.
Section 1
Waves Travel from a Source
A physical phenomenon begins with a disturbance. When a force disturbs a material, it creates a source of energy. This initial energy input becomes the starting point for a wave.
From this central point, the wave travels outward, spreading into the surrounding environment. This movement is not random; it forms a repeating, predictable pattern of motion that expands radially, much like ripples spreading across a surface.
Section 2
A Wave Transfers Energy
The primary function of a wave is the transport of energy. While the wave pattern itself creates the illusion that the material is moving across great distances, this is not the case.
The physical "stuff" the wave moves through, known as matter, mostly oscillates in place (moving up and down or back and forth) and returns to its original position. Therefore, a wave is defined as a disturbance that transfers energy from one location to another without permanently transporting the matter itself.
Section 3
A Wave Moves Energy, Not Water
Waves require a substance to travel through, which is called a medium. Whether this medium is a liquid, solid, or gas, its behavior remains consistent: it acts as a carrier.
As the wave passes, the particles of the medium vibrate temporarily to pass the energy along, but they do not travel with the wave. This distinction is crucial: the pattern of motion travels long distances, but the particles of the medium stay relatively local.
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Section 1
Waves Travel from a Source
A physical phenomenon begins with a disturbance. When a force disturbs a material, it creates a source of energy. This initial energy input becomes the starting point for a wave.
From this central point, the wave travels outward, spreading into the surrounding environment. This movement is not random; it forms a repeating, predictable pattern of motion that expands radially, much like ripples spreading across a surface.
Section 2
A Wave Transfers Energy
The primary function of a wave is the transport of energy. While the wave pattern itself creates the illusion that the material is moving across great distances, this is not the case.
The physical "stuff" the wave moves through, known as matter, mostly oscillates in place (moving up and down or back and forth) and returns to its original position. Therefore, a wave is defined as a disturbance that transfers energy from one location to another without permanently transporting the matter itself.
Section 3
A Wave Moves Energy, Not Water
Waves require a substance to travel through, which is called a medium. Whether this medium is a liquid, solid, or gas, its behavior remains consistent: it acts as a carrier.
As the wave passes, the particles of the medium vibrate temporarily to pass the energy along, but they do not travel with the wave. This distinction is crucial: the pattern of motion travels long distances, but the particles of the medium stay relatively local.
Book overview
Jump across lessons in the current chapter without opening the full course modal.
Continue this chapter