Dylan Zywicki 3-26-09 6th hour

What is a wave?* A wave is any disturbance that

transmits energy through matter or empty space.

* Some examples are;

1. Water waves in the ocean

2. Light waves from the sun

3. Microwaves inside of a microwave oven

4. Radio waves transmitted to the radio

5. (And) Sound waves from the radio, telephone, and voices

What is Wave energy?* Wave

energy is when 1 wave occurs, another wave should occur at the same speed.

What is a medium? What are 3 common mediums? What waves need a medium? Waves that need a medium

are called what?_______________________________* A medium is a substance through which a wave

can travel.

* Solids, liquids and gases can be mediums.

* Sound waves need a medium because it needs the particles in a solid, liquid or gas to vibrate.

* Waves that need a medium are called mechanical waves.

What are waves called that don’t need a medium?

* These are called electromagnetic waves.

* Visible light, microwaves, TV, radio signals and x rays are examples.

“All waves transfer energy

by repeated vibrations.”

What is a transverse wave? What does the word “transverse” mean?

* Transverse waves are waves in which the particles vibrate in an up and down motion.

* “Transverse” means “moving across”.

* An example is; a wave moving on a rope.

“All electromagnetic

waves are considered

transverse waves.”

What are longitudinal waves? What is a compression? What is a

rarefaction?* Longitudinal waves are a

wave in which the particles of the medium vibrate parallel to the direction of wave motion.

* A compression is a part of a longitudinal wave where the particles are crowded together.

* A rarefaction is a part of a longitudinal wave where the particles are spread apart.

* Example: A coil

What is it called when transverse and longitudinal waves combine?

How do the particles behave?* A surface wave is created when a transverse and longitudinal wave.

* They move in circles up and down.

* Example: A bottle in the ocean.

What is amplitude?How do you hear amplitude?

* Amplitude is the maximum distance that the particles of a wave’s medium vibrate from their rest position.

* You can hear amplitude depending on how far away from the resting position the sound wave is.

Amplitude

“Larger Amplitude –

More Energy.”

What is Wavelength?How do you hear Wavelength?

* Wavelength is the distance between any two crests or compressions next to each other in a wave.

* You can hear wavelength depending on how close or far away one wave is from the next wave. Also, how long it takes to get from one wave to another.

Longitudinal Wavelength

---versus---

Transverse Wavelength

Wavelength

“Shorter Wavelength – More Energy.”

What is Frequency?How do we measure frequency?

* Frequency is the number of waves produced in a given amount of time.

* We measure this in Hertz.

“Higher Frequency –

More Energy.”

What is the relationship of frequency and wavelength?

* Wavelength shows how far one point is to another and in how much time.

* Frequency shows how frequent something is. (Example: if a lakes waves goes at the same speed for 10 seconds and keeps the same up and down formation.

What is reflection?* A wave that bounces back after hitting a barrier.* Example; light waves from the sun are reflected on the moon.

“All waves - including water,

sound, and light - can be reflected.”

What is refraction?* Refraction is the bending of a wave as the wave passes from one medium to another at an angle.

* Example; refraction of a flashlight beam as the beam passes from the air to water.

What causes refraction?* When a wave goes into a different medium

(solid, liquid or gas) it causes refraction.

* Examples; A flashlight that goes from a gas medium, to a liquid medium. (refraction of a flashlight beam as the beam passes from the air to water.)

What results when light is refracted?

* It disperses (spreads out) when light is refracted.

* Example; refraction of a flashlight beam as the beam passes from the air to water.

What is diffraction?* Diffraction is the

bending of waves around a barrier or through an opening.

* Example; the sun’s light waves bending around a wall. Light

shine’s through an opening

Here’s the light reflected to the floor

“The amount of diffraction of a wave depends on its wavelength and the size of

the barrier or opening the wave encounters.”

* Example: you can hear music around the corner of a building because sound waves have long wavelengths and are able to diffract around corners.

What is Interference?

* Interference is the result of two or more waves overlapping.

* 2 types - constructive and destructive interference

* Example; two sound waves playing at the same time.

What is a standing wave?* A standing wave is a

pattern of vibration that simulates a wave that is standing still.

* Example; moving a rope at certain frequencies, the rope appears to vibrate in loops.

What is resonance or resonance frequency?

* Resonance is when an object vibrating at or near the resonant frequency of a second object causes the second object to vibrate.

* Example: when you sing in the shower (if you do), certain frequencies create standing waves in the air that fills the shower stall. It makes your voice sound louder.