Waves

The amplitude of a wave is

a measure of the displacement of the wave from its rest position.

a wave is

a traveling disturbance that travels through space and matter transferring energy from one place to another.

Frequency

# of full wavelengths that pass a fixed point in a certain time period. Metric unit Hertz (Hz) Symbol ƒ What is the frequency of the following wave?4 Hz

Examples of transverse waves

a water wave where the water moves up and down as the wave passes through the ocean, an oscillating string and a wave of fans in a stadium (the people move up and down while the wave moves around the stadium).

Examples of longitudinal waves

a wave moving through a stretched out slinky or spring, sound.

The line through the center of the wave is the

resting position

Microwaves are

shorter than radio waves with wavelengths measured in centimeters. We use microwaves to cook food, transmit information, and in radar that helps to predict the weather.

When drawing a wave or looking at a wave on a graph, we draw the wave as a

snapshot in time. The vertical axis is the amplitude of the wave while the horizontal axis can be either distance or time.

One example of a mechanical wave is

sound. Sound can travel through air, water, or solids, but it can't travel through a vacuum.

Another important property of a wave is the

speed of propagation. This is how fast the disturbance of the wave is moving. example, sound will travel at a different speed in water than in air.

The "medium" is the

substance or material that carries a mechanical wave.

The wavelength of a wave is

the distance between two corresponding points on back-to-back cycles of a wave. This can be measured between two crests of a wave or two troughs of a wave.

Wave Speed

Distance a wave moves in a certain amount of time. Depends on the medium. Speed = wavelength x frequency What is the speed of a wave that has a 10 m wavelength and a frequency of 4 hertz? Speed = wavelength x frequency = 10 m x 4 Hz = 40 m/s

Wavelength

Distance between 2 consecutive (one after another) wave points. Metric unit meters Symbol λ (lambda)

What is a wave?

Disturbance that transmits (carries) energy through matter or space.

Longitudinal Waves

Energy moves in parallel (back and forth) to the motion . Ex. Sound waves Compression areas of high energy (like the crest) Rarefaction areas of low energy (like the trough)

Amplitude

Greatest distance from the rest position. As the energy increases, the amplitude increases

Frequency is measured in

Hertz or cycles per second. The frequency is often represented by the lower case "f."

What is a matter & space?

Matter Solid, liquid, or gas Called a Medium. Space NOTHING

The Transverse Waves

Means "moving across" Energy moves in perpendicular (up and down or side to side) to the motion . Ex. Water waves

Transverse Waves

Rest natural rest position for the medium. Crest highest point of the wave, shows the highest amount of energy being carried. Trough Lowest point of the wave, show the lowest amount of energy being carried.

velocity

The velocity of a wave is usually represented by the letter "v." The velocity can be calculated by multiplying the frequency by the wavelength.

The mechanical waves

Two types of mechanical waves. Transverse Longitudinal Differ by the way they carry energy.

There are many properties that scientists use to describe waves. They include

amplitude, frequency, period, wavelength, speed, and phase.

Far infrared waves

are further away from visible light in wavelength.

Gamma rays

are the shortest waves in the spectrum and, as a result, have the most energy.

Near infrared waves

are the waves that are closer to visible light in wavelength.

Electromagnetic waves

are waves that can travel through a vacuum (empty space). They don't need a medium or matter. They travel through electrical and magnetic fields that are generated by charged particles.

Mechanical waves

are waves that require a medium. This means that they have to have some sort of matter to travel through.These waves travel when molecules in the medium collide with each other passing on energy.

Longitudinal waves

are waves where the disturbance moves in the same direction as the wave.

Transverse waves

are waves where the disturbance moves perpendicular to the direction of the wave.

Ultraviolet waves

ave the next shortest wavelength after visible light. It is ultraviolet rays from the Sun that cause sunburns.

highest point on the graph of the wave is called the

crest

Waves can be divided into various categories

depending on their characteristics.

Another way to describe a wave is by the

direction that its disturbance is traveling.

Electromagnetic waves are a form of

energy waves that have both an electric and magnetic field. Electromagnetic waves are different from mechanical waves in that they can transmit energy and travel through a vacuum.

X-rays

have even shorter wavelengths than ultraviolet rays. At this point in the electromagnetic spectrum, scientists begin to think of these rays more as particles than waves. X-rays were discovered by German scientist Wilhelm Roentgen.

The electromagnetic wave

radio waves, microwaves, infrared waves, visible light, ultraviolet waves, x-rays, gamma waves

Anything that gives off heat radiates

infrared waves. This includes the human body!

Between microwaves and visible light are

infrared waves. classified as "near" infrared and "far" infrared.

Examples of electromagnetic waves

light, microwaves, radio waves, and X-rays.

Radio waves have the

longest wavelengths of all the electromagnetic waves. They range from around a foot long to several miles long. Radio waves are often used to transmit data and have been used for all sorts of applications including radio, satellites, radar, and computer networks.

Sound is a type of wave that moves through

matter and then vibrates our eardrums so we can hear.

The amplitude is a

measure of the strength or intensity of the wave.

All waves can be categorized as either

mechanical or electromagnetic.

Many waves cannot be seen such as

microwaves and radio waves.

The frequency of a wave is the

number of times per second that the wave cycles

The visible light

pectrum covers the wavelengths that can be seen by the human eye.

Light is a special kind of wave that is made up of

photons that helps us to see.

As the wavelengths of electromagnetic waves get shorter,

their energy increases.

The period of the wave is the

time between wave crests. The period is usually represented by the upper case "T."

One of the most important things to remember about waves is that they

transport energy, not matter. This makes them different from other phenomenon in physics.

the lowest point is called the

trough.

Other examples of mechanical waves

water waves, seismic waves, and waves traveling through a spring.

Example of amplitude

when looking at a sound wave, the amplitude will measure the loudness of the sound.