Wave Properties Waves In General Waves are energy

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Wave Properties

Wave Properties

Waves In General: • Waves are energy traveling through a “medium” (solid, liquid or

Waves In General: • Waves are energy traveling through a “medium” (solid, liquid or gas material) • Properties of waves depend on elasticity of the medium: Sound speeds in different mediums Air (0 degrees) 331 m/s Air (20 degrees) 343 m/s As you can see, sound travels at different speeds depending on the medium Water 1500 m/s Think: Why would waves move through solids faster than a gas like “air”? Iron 4400 m/s Glass 5100 m/s

Sound Travel in “Space”: So if the astronauts communications device fails, If there Think:

Sound Travel in “Space”: So if the astronauts communications device fails, If there Think: isn’t What enough is missing atomsfor (“air”) the energy out there, of So can any sounds out there all? the can they takethere theirbe helmets off (don’t worryat about can the sound to energy travelactual between travel them? anywhere? whole “breathing” thing here) and just talk?

Properties of Waves: They may not look like much, but waves have several features

Properties of Waves: They may not look like much, but waves have several features that we use to describe what result the energy will have:

Wavelength: The distance between any point on a wave and the equivalent point on

Wavelength: The distance between any point on a wave and the equivalent point on the next phase. Literally, the length of the wave. It is either the distance between two different tops of waves Or the distance between two different bottoms of waves, either way, it will be the same!

Amplitude: The strength or power of a wave signal. The "height" of a wave

Amplitude: The strength or power of a wave signal. The "height" of a wave when viewed as a graph. The Amplitude is the height of a wave from bottom to top

Amplitude = Loudness How we sense Amplitude = Loudness Higher amplitudes are interpreted as

Amplitude = Loudness How we sense Amplitude = Loudness Higher amplitudes are interpreted as a higher volume, hence the name "amplifier" (or “amp’s”) for a device which increases amplitude. More Amplitude means more height! Less Amplitude means less height! Think: Which wave will have a louder sound?

Frequency: The number of times the wavelength occurs in one second. (Like waves per

Frequency: The number of times the wavelength occurs in one second. (Like waves per second) The faster the sound source vibrates, the faster the wave and the “higher” the frequency. 1 second Low High

How Frequency Affects Sound: How we sense Frequency = “Pitch” Higher frequencies are interpreted

How Frequency Affects Sound: How we sense Frequency = “Pitch” Higher frequencies are interpreted by our brain as a higher pitch. For example; when you sing in a high-pitched voice you are forcing your vocal chords to vibrate quickly. (Also note that high frequency = high energy. ) “High” note = High Frequency “Low” note = Low Frequency Our ears are sensitive to sound energy. We perceive a high Notice: Did as the Amplitude when we changed frequency? frequency a high pitched change note; a low frequency as a lowthe pitched note.

“Light” Spectrum: A graph that shows the different frequencies of light waves and the

“Light” Spectrum: A graph that shows the different frequencies of light waves and the resulting types of light and colors. Light Frequency = Type of light and color Higher frequencies are interpreted as different types light. For example; a higher frequency can make a darker color. Radio | Micro | Infra Red | Visible Light | UV | X-Ray | Gamma Notice that low Frequencies make radio, micro, and Infrared waves of energy Also different Frequencies make colors. This is the only type of light Humans can see. Higher Frequencies make Ultraviolet, X ray, and Gamma waves of energy Lastly: Notice that all These Waves have the same amplitude!

So what is White Light? White Light is actually made up of many different

So what is White Light? White Light is actually made up of many different colors – each color is made up of its own frequency and wavelength. When you combine the colors together it actually makes white light! You can shine white light into a prism and it separates it out into the mix of colors

Notice the white light coming in Notice the split spectrum coming out.

Notice the white light coming in Notice the split spectrum coming out.

Wave Speed: • Average Wave Speeds: can vary depending on the type of energy

Wave Speed: • Average Wave Speeds: can vary depending on the type of energy 8 3. 0 x 10 m/s Light = Sound ≈ 340 m/s (Faster than most jets) Of course it still depends on what medium the Energy is travelling through!!!

Why we see the firework first – then hear it after? Light travels faster

Why we see the firework first – then hear it after? Light travels faster than Sound!!!

Hammering It takes longer for the sound energy To reach your ear than for

Hammering It takes longer for the sound energy To reach your ear than for the light Energy to reach your eye! That’s why we can see something before we can hear it!

Since waves propagate in 3 D, we can see the light from this candle

Since waves propagate in 3 D, we can see the light from this candle in all directions. Same thing applies with sound.

Wave motion is like an onion: Spreads out in all directions equally! Think about

Wave motion is like an onion: Spreads out in all directions equally! Think about it; is there any direction (up down, left, right…etc…) that the sun DOESN’T shine it’s light and heat energy? Intensity: The further out you go from the energy source, the less intense the wave is. The reason the farther out planets are “colder” is because they are farther from the source of the heat and light in our solar system. EX: If you wanted to save your ears from the loudness of the speakers – scoot back!

Movement of Waves: The layers of an onion, are a good representation of how

Movement of Waves: The layers of an onion, are a good representation of how waves look as they travel In every direction equally at the same time! HEY! I’ve got layers too!!! The exception is “surface waves” (like wind generated ocean waves). They only travel on a “surface” (not up and down).

Common Instruments we use to sense light energy in our lives Glasses Telescope MRI

Common Instruments we use to sense light energy in our lives Glasses Telescope MRI Machine Satellite Dish

Common Instruments we use to sense light energy in our lives Microphone Hearing Aid

Common Instruments we use to sense light energy in our lives Microphone Hearing Aid Sonar Stethoscope Ultrasound