Mechanical Waves 17.1

​Mechanical Waves & Sound

​Mecchanical Wave

A mechanical wave is created when a source of energy causes a vibration to travel through a medium.

• ​Mechanical Wave: is a disturbance in matter that carries energy from one place to another.

• Medium: The material through which a wave travels

​The three main types of mechanical waves

1. transverse waves


2. longitudinal waves


3. surface waves.

​Transverse wave

• causes the medium to vibrate at right angles to the direction in which the wave travels.

Crest: The highest point above the rest position

​Trough The lowest point below the rest position

Wavelength is the distance between corresponding points on a wave, such as two consecutive crests or troughs. It

​Longitudinal wave

Compression.- an area where the particles in a medium are spaced close together

​ - causes the medium to vibrate parallel to the direction the wave travels.

​Rarefaction- An area where the particles ina medium are spread out

Surface wave

• a wave that travels along a surface separating two media.

​Surface Wave particles of the medium move up and down, and back and forth. When these two motions are combined, the particles move in circles.

Multiple Choice

What kind of wave is pictured below?

• compressional wave

• transverse wave

• sound wave

• mechanical wave

Multiple Choice

Which wave is pictured?

• Transverse
• Longitudinal
• Both
• Neither

Multiple Choice

The material through which a wave travels

• Mechanical Wave

• Medium

• Crest

• Trough

Labelling

Label the Transverse Wave

Drag labels to their correct position on the image

Trough

Crest

Labelling

Label the longitudinal wave

Drag labels to their correct position on the image

Rarefaction

Compression

Multiple Choice

Which is true of a mechanical wave?

• It must have a medium
• It must travel in empty space.
• It can travel in a vacuum.
• Both sound and light are examples.

Multiple Choice

Unlike a transverse wave, the disturbance in a longitudinal wave is

• in a circular motion.
• parallel to the wave motion.
• perpendicular to the wave motion.
• in the opposite direction of the wave motion

Multiple Choice

Which is true about a surface wave?

• It only has properties of transverse waves.
• It only has properties of longitudinal waves.
• has neither properties of transverse or longitudinal waves.
• It has properties of both transverse and longitudinal waves.