Media: Which material can a wave NOT travel through? Air Water Steel Wood 5. They are all media!

Wavelength, Amplitude, Frequency Basics

New Vocab:

Wavelength (𝜆) is: The distance between successive parts of a wave. The distance from crest to trough. The number of cycles per second. The distance from a crest or trough to point of equilibrium.

Wavelength looks like: 𝜆 𝜆

An example of wavelength (𝜆) is:

Which is an example of Amplitude (A)? 3. 4. A A A

All Together Now:

Frequency ( f ) for waves: Creation of standing wave: As wave pulse moves past: Number of times you move your hand back and forth per second. Number of waves moving past a point per second.

Units for each? Wavelength: Amplitude: Frequency: meters (m) Transverse waves like slinky, water, etc: meters (m) Longitudinal waves like sound, etc: Newtons (N) Frequency: Cycles per second ( 𝑐𝑦𝑐𝑙𝑒 𝑠 ) or ( 1 𝑠 ) Will be referred to as Hertz (𝐻𝑧)

Advanced Waves Check In Interference

When two wave pulses interfere destructively, they will: Combine to form a larger amplitude wave. Combine to form two waves. Combine to cancel out energies permanently, completely destroying the waves. Combine to cancel out only while they have met.

When two wave pulses are sent as pictured and meet in the middle, they will meet, and: then reflect off of one another. pass through each other. completely die out, and then create new waves which continue moving on the other half of the medium, creating the illusion of passing through the other wave. completely die out, and then create new waves on the same half of the medium, creating the illusion of reflection.

Constructive interference means that when two waves meet, they: Combine to form a larger amplitude wave. Combine to form a two waves. Combine to cancel out energies permanently, completely destroying the waves. Combine to cancel out only while they have met.

A standing wave is created because: 1 person moves 1 side of the slinky, and that movement needs to be continued to keep a wave going. 1 person moves 1 side of the slinky, that wave travels down the slinky and reflects back, creating constructive and destructive interference in the pattern of a wave.

Constructive/destructive always destructive

Waves changing media

When a wave travels from a slinky (faster medium) to a spring (slower medium), All of the wave will reflect back onto the faster medium. Some of the wave will reflect back onto the faster medium, the rest will be converted to thermal energy in the slower medium. Some of the wave will reflect back onto the faster medium, the rest will be transferred as a wave onto the slower medium.

1 2 𝜆 1 2 𝜆

When a wave travels from a spring (slower medium) to a slinky (faster medium), All of the wave will reflect back onto the easier medium. Some of the wave will reflect back onto the slower medium, the rest will be converted to thermal energy in the faster medium. Some of the wave will reflect back onto the slower medium, the rest will be transferred as a wave onto the faster medium.

1 2 𝜆 1 2 𝜆

Will stay the same. Will increase. Will decrease. When a wave travels from a spring (slower medium) to a slinky (faster medium) the wavelength: Will stay the same. Will increase. Will decrease.

1 2 𝜆 1 2 𝜆

Whenever a wave travels from a faster medium to a slower one, the amplitude of the two reflected waves will be: Larger than the original wave The same size as the original wave Smaller than the original wave

A

Basics Review

How can we increase the wavelength of wave(s) in a single medium? Increase the frequency Decrease the frequency Increase the amplitude Decrease the amplitude

How can we increase the amplitude of wave(s) in a single medium? Increase the frequency Decrease the frequency Move hand and slinky farther from equilibrium Move hand and slinky closer to equilibrium

The velocity a wave may travel is dependent on: The frequency The wavelength The physical properties of the medium Constructive interference

Water Spring Same for both. If a transverse wave travels faster on our spring than in water, and we wanted to create wavelength of 1m in both media, which would need a higher frequency? Water Spring Same for both.