AKS 9a, b, and d Review

Amplitude

• Amplitude is the maximum distance the particles vibrate from the rest position.

• Rest position is the place where the particles of a medium stay when there is no disturbance. The taller the wave = larger amplitude

• The taller the wave = larger amplitude

Poll

If a wave has a small amplitude, do you think it has low energy or high energy?

• Low energy

• High Energy

Amplitude & Energy

• Small amplitude = low energy

• Large amplitude = high energy

Measuring Amplitude on a Transverse Wave

• Measured from the rest position to the crest or trough of the wave

Measuring Amplitude on a Longitudinal Wave

• It is difficult to show amplitude on this wave.

• Amplitude of a longitudinal wave is related to how tightly packed the compressions are.

• The tighter the packing = greater amplitude

Wavelength

• Wavelength is the distance from any point on a wave to an identical point on the next wave

Wavelength on Transverse Waves

• The distance between two adjacent crests

• OR the distance between two adjacent troughs

Wavelength on Longitudinal Waves

• The distance between two adjacent rarefactions

• OR the distance between two adjacent compressions

Wavelength & Energy

• The shorter the wavelength the greater the energy

• OR the longer the wavelength the lower the energy

• They are inversely proportional

• The symbol for wavelength is the Greek letter lamda--> λ

Frequency

• The number of vibrations (waves, cycles) that occur per second

• Unit is Hertz (Hz)

• 1 Hz = one wave per second

• High frequency carry high energy

Frequency in Transvese Waves

• Frequency is measured by the number of crests OR troughs that pass a certain point over a certain amount of time

Frequency in Longitudinal Waves

• To find the frequency, count the number of compressions or rarefactions.

Multiple Choice

Which wave carries more energy?

• Wave A

• Wave B

Labelling

label this wave diagram

Drag labels to their correct position on the image

sound

medium

mechanical

Energy

electromagnetic

light

​​Mechanical waves

• ​The speed at which they travel depends on either the type of wave or the medium they are in.

• ​

• ​They travel fastest in more dense medium. Therefore, they move fastest in solids and slowest in gases.

• ​

• ​Generally, these have longer wavelengths than electromagnetic waves.

​Electromagnetic waves

• ​All electromagnetic waves travels at the speed of light 3.0 x 10⁸ m/s in a VACUUM. However, they travels at different speeds when traveling through matter.

• They travel fastest in less dense medium, so fastest in gases and slowest in solids.

• Ex: Radio waves, Microwaves, Infrared, Visible Light, Ultraviolet, X-rays, and Gamma Ray.

Multiple Choice

Which type of waves must have a medium in order to travel?

• electromagnetic wave

• mechanical wave

Multiple Choice

Mechanical waves usually travel fastest through:

• solids

• liquids

• gases

Multiple Choice

What type of wave is this?

• Electromagnetic

• Mechancial

• Both Electromagnetic and Mechanical

Multiple Choice

A microwave is an example of what type of wave?

• electromagnetic wave

• mechanical wave

Multiple Choice

A water wave is an example of what type of wave?

• electromagnetic wave

• mechanical wave

Multiple Choice

Wave with the longest wavelength

• microwave
• radio
• gamma
• visible light

Multiple Choice

When the wavelength increases the frequency will

• increase

• decrease

• remain same

• none of these

Multiple Choice

Electromagnetic waves  

• Must travel through a vacuum

• Can travel through a medium or a vacuum

• Are the same type of wave as mechanical waves

• Can only travel through a vacuum

Multiple Choice

All electromagnetic waves have the same...

• frequency
• speed
• wavelength
• energy

Multiple Choice

When a wave is travelling through matter, what happens to the matter?

• The matter is pulled along behind the wave as that makes it a longitudinal wave.

• The wave is making the matter move back and forth as that will make a transverse wave.

• The wave is making the matter move up and down.

• The matter is pulled along behind the wave as that makes it a compressional wave.

• The matter does not move along with the wave.

Multiple Choice

It depends on the medium in which the wave is traveling. It varies in solids, liquids and gases.

• Frequency

• Wave speed

• Amplitude

• Wavelength