Wave Mechanics

Wave Mechanics

A wave is a disturbance through a medium that carries energy from one place to another.

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​Fun fact: Sound is an example of a wave!

​What is a wave?

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​Can travel in empty space

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Ex: UV rays, radio waves​, gamma waves

​Electromagnetic

​Requires a medium

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​Ex: Sound, ripples in a pond, springs

​Mechanical

Types of waves

Fun fact: ​The gamma waves that transformed Bruce Banner into The Hulk, would have killed him. #BadMoviePhysics

Multiple Choice

This crazy Karen is screaming at a poor grocery store clerk. What is the medium that her sound energy is traveling through?

• Water

• Air

• A slinky

• Her never ending Karen-rage

Multiple Choice

MATH REVIEW!!!

Which one of these show lines that are perpendicular?

​Transverse Waves

Transverse waves​ cause the particles of the medium to move perpendicular to the direction the wave is traveling.

Fun fact: The largest ocean wave ever recorded by ​humans was 1,720 ft tall!

​Fun Fact: The original slinky sold for $1.

​Transverse Waves

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​Longitudinal Waves

A Longitudinal wave causes the particles of the medium to move parallel to the direction the wave is traveling.

Fun Fact: Drummers are awesome, man! Hitting a drumhead makes it move inwards and outwards, making air particles move in the same direction!

​Longitudinal Waves

Multiple Choice

Which one is an example of a transverse wave?

Low vs High Frequency

Frequency - ( f ) - The number of waves per second.

• 1 cycle per second = 1 H​ertz (Hz)

• Does not change from one medium to the other.

Period ( T ) - measured in seconds.

​The number of seconds per wave.

Fun fact: The period of revolution for our Earth around the sun is 364.25 days.

​Frequency vs Period

Amplitude - (A)

The maximum displacement of particles in a medium from the point of equilibrium.

Height from "rest to crest"

Wavelength (λ) - meters

The distance between any two consecutive points in phase.

Fun Fact: Our eyes recognize each wavelength by a different colour.

Multiple Choice

On the picture, which letter represents the wavelength of the wave?

• A

• B

• C

• D

Speed (v) - (m/s)

The speed​ of wave depends on the properties of the medium it is traveling through.

Fun Fact: Waves in the ocean are mostly generated by the wind moving across the ocean surface

Multiple Choice

A wave with a frequency of 14 Hz has a wavelength of 3 meters. At what speed will this wave travel? $$v=\lambda f$$  

• 4.7 m/s

• 42.0 m/s

• 53.6 m/s

• 24.0 m/s

Principle of Superposition

When two waves are traveling independently through the same medium, the resultant displacement of any particle at a given time is the vector sum of the displacements that the individual waves acting alone would give it.

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When two waves pulses encounter each other, the wave pulses with superpose beyond the barrier. This is called wave interference.​

Two waves combine to make a resultant bigger wave.

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​Constructive Interference

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Two waves combine to make a resultant smaller wave.​

Deconstructive Interference

Multiple Choice

If wave A has an amplitude of 5 meters, and wave B has an amplitude of 6 meters, what is the height of the wave at superposition?

• 0 m

• -1 m

• 35 m

• 11 m