1. Chp Mechanical Waves Pg

2. Mechanical Waves
Mechanical Wave = a disturbance in matter that carries energy from one place to another
Medium - the material through which a wave travels
Solids, liquids, and gases can all act as mediums
Mechanical waves require a medium (or matter) to travel through. They cannot travel through empty space
In a wave pool, waves travel through the water and carry energy across the pool. The water is the medium.

3. Mechanical Waves
A mechanical wave is created when a source of energy causes a vibration to travel through a medium
Vibration is a repeating back and forth motion
When you shake a rope, you add energy at one end, and the wave that results is a vibration that carries along the rope. The rope is the medium

4. Types of Mechanical Waves
The three main types of mechanical waves are
Transverse waves
Longitudinal waves
Surface waves

5. Wave Parts
Crest - the highest point of the wave above the rest position
Trough - the lowest point below the rest position
Wavelength - the distance between a point on one wave and the same point on the next cycle of the wave
Amplitude - the maximum displacement of the medium from its rest position

6. Transverse Wave
A wave that causes the medium to vibrate at right angles to the direction in which the wave travels
When you shake one end of a rope the vibration causes a wave. Notice the wave carries every from left to right, in a direction perpendicular to the up- and-down motion of the rope
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7. Longitudinal Wave
A wave in which the vibration of the medium is parallel to the direction the wave travels
The vibration is a back-and-forth motion in the same direction or parallel to the direction in which the wave moves
Compression - area where the particles in a medium are spaced close together
Rarefaction - area where the particles in a medium are spread out

8. Longitudinal Waves Examples Waves in a slinky or spring
Primary waves (P waves) - longitudinal waves produced by earthquakes
P waves travel through the earth. Scientists can use these waves to map Earth’s interior
Click this image to see animation

9. Surface Waves A wave that travels along a surface separating two media
Occurs when the up-and-down motion and the back-and-forth motions of transverse and longitudinal waves combine creating a circular motion (in deep water). Does not cause movement of debris.
As a wave enters shallow water, the bottom of the wave slows because of friction and the top of the wave continues moving at the same speed. This causes the wave to topple over on itself or “break”. Breaking waves can carry debris to shore.

10. The End
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