Waves in AIr, Fluids and solids

What are two types of waves?

1. Transverse

2. Longitudinal

What is a transverse wave?

A wave for which the oscillations are perpendicular to the direction of energy transfer

What is a longitudinal wave?

A wave for which the oscillations are parallel to the direction of energy

Give two examples of transverse waves

1. Electromagnetic waves

2. Seismic s-waves

Give two examples of longitudinal Waves

1. Sound waves

2. Seismic p-waves

What are the two parts of a longitudinal wave called?

Compression and rarefractions

What is a wave’s amplitude?

The maximum displacement of a point on a wave from its undisturbed position

What is wavelength?

• The distance from a point on a wave to the same position on the adjacent wave

• Most commonly peak to peak or trough to trough

What is the frequency of a wave?

The number of waves that pass a given point of each second

What is the unit used for frequency?

Hertz, Hz

What is meant by a frequency of 200Hz?

200 Waves pass a given point each second.

What is wave speed?

The speed at which the wave moves or at which energy is transferred through a medium.

What does a wave transfer?

Energy

State the equation used to calculate wave speed. Give appropriate units:

Wave speed = Frequency x Wavelength

Speed (m/s), Frequency (Hz), Wavelength (m)

What word is used to describe when a wave bounces off a surface

Reflection

How do sound waves travel through a solid?

The particles in the solid vibrate and transfer kinetic energy through the material.

What is the frequency range of human hearing?

20 Hz - 20kHz

(1kHz = 1000 Hz)

What are ultrasound waves?

Waves which have a frequency higher than the upper limit of human hearing

Give an example use for ultrasound waves?

Medical or industrial imaging.

What natural even causes seismic waves to be produced? What types are produces?

• Earthquakes

• They produce both P-waves and S-waves

State a difference between the mediums that p-waves and s-waves can travel through.

• P-waves travel through both solids and liquids

• S-waves only travel through solids

What technique is used to detect objects in deep water and measure water depth?

• Echo sounding

• High frequency sound waves are emitted, reflected and detected

• Time difference between emission and detection, alongside wave speed, are used to calculate distances