Science: LQ 1 Review

Electromagnetic Waves

Electromagnetic Waves

Electrical and Magnetic disturbance that moves through space at the speed of light. (They can travel through empty space)

Electromagnetic Spectrum

EM Waves are often classified by frequency in a schemem called _______

Frequency

The _____ of the wave produced is the number of complete vibrations per second.

frequency and speed

The wavelength of an EM wave depends on its_______.

frequency and wavelength

The waves differ in the way they are produced and interact with matter and from each other in their _____ and ______

Band

Each type of wave occupies a particular range of wavelengths known as _______

Photon

A throbbing pulse of electromagnetic radiation is called ______

Radio Waves

Longest wavelengths and shortest frequencies in the EM Spectrum. Used to transmit radio and television signal.

Global Positioning Systems (GPS)

Measure the time it takes a radio wave to travel from several satellites to the receiver, determining the distance to each satellite.

AM Radio Waves

A type of radio wave that readily bends around builings and other objects that might be present in their path

FM Radio Waves

Type of radio wave that has a shorter wavelength than the AM waves

Radio Frequency

A rate of oscillation in the range of about 3 kHz to 300 GHz, which corresponds to the frequency of radio waves, and the alternating currents that carry radio signals

Microwaves

They are basically extremely high frequency radio waves and have the shortest wavelengths. They have very short wavelengths ranging from approximately 1 millimeter to 30 centimeters.

RADAR (Radio Detection and Ranging)

Used to find the speed of an object by sending out radio waves and measuring the time it takes them to return.

Infrared

A picture that shows regions of different temperatures in the body.

Near Infrared Light

The closest in wavelength to the visible light

Far Infrared Light

Type of Infrared which is closer to the microwave region of the EM spectrum

Thermography/Pyrometry

Determining the temperature of objects

Visible Light

Portion of the EM spectrum that is visible to the human eye.

Ultraviolet

EM radiation with a wavelength shorter than that of visible light, but longer than x-rays

UV Radiation

This is produced by high-temperature surfaces, such as the sun.

X-rays

High-energy waves which have great penetrating power and are used extensively in medical applications and in inspecting welds.

Gamma Rays

Generated by radioactive atoms and in nuclear explosions, and are used in many medical applications.

Gamma Knife Surgery

A procedure wherein multiple concentrated beams of gamma rays are directed on the growth in order to kill cancerous cells.

Electromagnetic Radiation

Energy produced by nuclear reactions at the core of the sun

Radiation

Can be defined as the process of emitting energy by any particles, such as in the case of high-energy, protons, neutrons, atoms, and ions, and waves, either light or sound,

Radioactive Materials

Are composed of unstable atoms that give off its excess energy until it becomes stable

Radioactive Decay

Happens during the spontaneous change of an atom to be more stable

Ionizing Radiation

An especially damaging form of radiation which can create electrically charged ions in the material it strikes

Ionization Process

Break apart atoms and molecules, causing severe damage in living organism

Sievert

Basic unit used to measure exposure to ionizing radiation

Millisieverts or microsieverts

Radiation exposure is expressed in _

1000 microsieverts

An average person is exposed to ___ of whole body exposure per year from all sources

Crest

What part is at number 1?

Wavelength

What part is at number 2

Trough

What part is at number 3?

Amplitude

What part is at number 4?

Transverse Wave

What kind of wave is this?

Waves

Disturbances in space and time, they cannot propagate without a medium and they cannot travel in a vacuum or empty space

Light Waves

Form of an EM Wave that is propagated perpendicular to the source of the energy.

NOTE: They travel in a straight path

Refraction, Reflection and Absorption

Properties of Light

Refraction

It is the bending of light as it travels through one medium to another with different refractive indices

Refractive Index

Relative quantification of how a medium propagates a specific wavelength of light

Reflection

It is when light bounces off an object

Virtual, Upright and Reversed

An image formed on a plane mirror is _______

Incident Ray

Light striking the plane mirror

Angle of Incidence

An angle formed by the incident ray

Normal Vector

An imaginary line perpendicular to the surface of the plane mirror.

Reflected Rays

Formed when light strikes the surface of an object

Law of Reflection

The angle of incidence is equal to the angle of reflection

Virtual Image

Image that apperas in a different location than its actual location

Newtonian Physics

There is no speed greater than light; thus, the indices of refraction of different materials are always greater than 1

Transmission

Refers to the process where light passes through an object or medium without being absorbed

Transmittance

Ratio between absorbed light and the incident light. it is unitless and it is used to examine how efficient a medium is in transmitting light.

Absoprtion

Occurs as light passes through a medium with the same natural frequency

Prism

Medium that diffracts light

ROYGBIV

The seven colors

Rainbow

A manifestation that indeed light is composed of seven colors

Spectrum

Components of ight with varying wavelengths

Light

It has both the properties of a wave.

Incident Ray

Beam in the first medium. It hits the boundary at an angel of incidence

Refracted Ray

Beam in the second medium. it leaves at an angle of refraction

Bends toward the normal

When light moves from air to water it _______. Making the angle of incidence greater than the angle of refraction

Slower

Light bending toward the normal indicates the speed is ____

Faster

Light bending away from the normal indicates the speed is _____.

Equal

The angle of incidence is ____ to the angle of refraction

Snell's Law

Describes the relationship between the angle or incidence and the angle of refraction.

Ratio of the sine of the angle of incidence to the sine of the angle of refraction is a constant

Medium and the density

Degree to which light is bent depends on the ____ and the _____ of the medium.

Index of refraction

Light going from a vacuum into another medium is called _____

Medium

Speed of light is dependent on the properties of the _____

Optical density

Determines how much energy is absorbed and re-emitted in a medium and determines the speed of the light in the medium

Higher, slower

The ____ the optical density, the ____ the light wave.

Energy

Light wave is transporting _____

Reflected

When light hits a boundary. Some energy is transmitted to the new medium, some energy is _______

Diamonds

______ sparkle because most of the light rays hitting the stone are internally reflected

Fiber Optics

Transmit information in pulses of light. used in telecommunications, computer networking, by mechanics, and doctors.

n = sin (angle of incidence) / sin (angle of refraction)

Equation for Snell's Law:

Images

Are formed when light strikes a reflecting surface, such as mirror or a lens

Slows light progress

(The presence of material) Interactions with electrical properties of atoms will ____.

Real Image

Image is made from "real" light rays that converge at a real focal point. Can be projected onto a screen and it is always inverted.

Virtual image

"Not Real" because it cannot be projected, the Image only seems to be there.

Virtual

If light energy doesn't flow from the image, the image is _____

Curved Mirrors

Is a mirror with a curved reflecting surface.

Convex and Concave

2 Types of Curved Mirrors

Concave Mirrors

A type of mirror that curves inward and may form a real or virtual image

Convex Mirrors

A mirror that curves outward, reduces image and forms virtual images.

Index of refraction

The "light slowing factor" is called the _____.

Convex Lenses

Lens that converges. Thicker in the center than edges. Forms real images and virtual images depending on position of the object.

Near Sighted

Eyeball is too long and image focuses in front of the retina.

Near Sightedness

Concave lenses expand focal length

Far Sighted

Eyeball is too short so the image is focused behind the retina

Far Sightedness

Convex Lens shortens the focal length