PH13.2 Intro to waves

PH13.2

Introduction to waves​

By Ms. Mecia

• Waves are a transfer of energy

• Waves are periodic disturbances in media or fields

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What are waves?

A medium is anything made of particles that a wave passes through or into

Mechanical waves

• ​Waves that propagate through a medium are called mechanical waves

• Mechanical waves must have particles to propagate

• Mechanical waves oscillate particles in a medium.

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Typically describes the repeating motion of particles, fields, or objects​

Oscillation

Typically describes the repeating motion of objects

Vibration

Typically describes the repeating motion of fields

Fluctuation

Oscillation = repeating motion

Multiple Select

Oscillate refers to the _ motion of a particle or field

• Circular

• Repeating

• Vibrating

• Fluctuating

• Propagate = "to create more"

• Propagate = "to move through"

Wave propagation

Multiple Choice

Water waves propagate through a _ medium.

• gas

• liquid

• solid

• All of the above

Multiple Choice

Seismic waves can propagate through

• Gases

• Liquids

• Solids

• All of the above

Multiple Choice

Sound waves can propagate through

• Gases

• Liquids

• Solids

• All of the above

• Electromagnetic waves propagate in vacuums and media

Electromagnetic waves

Multiple Choice

Electromagnetic waves propagate through

• Solids, liquids, and gases

• Solids, liquids, gases, and vacuums

• Vacuums

Open Ended

How do you know electromagnetic waves don't need particles to propagate?

What causes waves?

A disturbance causes a wave.​

Multiple Choice

What is the causing the wave?

• Air

• Water

• The plane

• All of the above

Multiple Choice

What is the causing the wave?

• The monkey's motion

• De-excitement of electrons

• The particles in the mirror

• All of the above

Multiple Choice

What is causing the wave?

• The creepy girl

• The water

• god only knows

• All of the above are reaosnable

Particles/fields oscillate perpendicular to propagation​

Transverse waves

Particles oscillate parallel to propagation​

Longitudinal waves

Waves oscillate particles/fields relative to propagation

Multiple Choice

A mechanical transverse wave causes _ to propagation

• PARTICLES to oscillate PARALLEL

• PARTICLES to oscillate PERPENDICULAR

• FIELDS to oscillate PARALLEL

• FIELDS to oscillate PERPENDICULAR

Multiple Choice

A mechanical longitudinal wave causes _ to propagation

• PARTICLES to oscillate PARALLEL

• PARTICLES to oscillate PERPENDICULAR

• FIELDS to oscillate PARALLEL

• FIELDS to oscillate PERPENDICULAR

Wave diagrams

Multiple Choice

An electromagnetic wave causes _ to propagation

• PARTICLES to oscillate PARALLEL

• PARTICLES to oscillate PERPENDICULAR

• FIELDS to oscillate PARALLEL

• FIELDS to oscillate PERPENDICULAR

What's in a wave diagram?

• Wavelength = a measure from one point to another point in-phase on the wave

• Wave amplitude = how far a particle oscillates from its equilibrium position​

Open Ended

Label each part of the wave using the terms: positive amplitude, negative amplitude, equilibrium position, and/or wavelength

Let's do some practice. Write your work on a sheet of paper and upload the work to the next slide.

Open Ended

Upload your work here. Ensure work is properly oriented.

Describes the relationship between wave speed, wavelength, and wave frequency

Wave equation

Wave characteristics

• Wavelength is a measure of the distance between two points in-phase on a wave

• Wave frequency is a measure of how many waves pass a point in one second

• Wave speed is a measure of how fast a wave travels

• Wave amplitude is a measure of how much energy a wave carries or how far particles move from equilibrium position

Multiple Select

Wavelength depends on the medium and the source disturbance. Which statement is true?

• $$\lambda\propto v$$  

• $$\lambda\propto f$$   

• $$\lambda\propto f^{-1}$$  

• $$\lambda\propto v^{-1}$$  

Wave speed, v

• Wave speed is determined by the properties of the medium or vacuum a wave propagates through

Multiple Choice

• Transverse mechanical waves move faster than longitudinal

• Longitudinal waves move faster than transverse mechanical waves

• No conclusive statements can be determined

Multiple Choice

A medium with particles that are difficult to move from equilibrium position cause a _ wave speed

• faster

• slower

Open Ended

A wave will continue to propagate after it has caused one complete oscillation. Why would a medium with difficult to move particles increase wave speed?

Wave frequency

• Wave frequency is determined by the source

Multiple Choice

A high frequency means

• a faster wave in a shorter time

• a longer wave in a shorter time

• more waves in a second

• fewer waves in a second

Multiple Choice

Which shows a transverse wave?

Wave amplitude

• Wave amplitude is determined by the energy the source

• Determined by the properties of the medium

Multiple Choice

Which wave has a greater amplitude?

Multiple Choice

Which disturbance will cause a higher energy wave?

Let's do some practice. Write your work on a sheet of paper and upload the work to the next slide.

Open Ended

Upload your work here. Ensure work is properly oriented.