RADT 142 Exam 2 part 2

2 kinds of waves

mechanical

electromagnetic (EM)

Mechanical Waves

transfer energy as they travel through matter

sound, water

Electromagnetic Waves (EM)

don’t need matter to transfer energy

x-ray, light

What are sine waves used for

to represent electromagnetic energy

Wavelength

distance between one crest to another

Amplitude

distance wave rises/falls from its postion

Frequency

number of waves (cycles) that pass in a second

Hertz (Hz)

EM wave characteristics

• have wavelengths, frequency, amplitude

• travel at speed of light

• travel in vacuum (empty of space)

how are frequency and wavelength related

inversely related

frequency up, wavelength down

how are energy and frequency related

directly proportional

T or F: increase in frequency will increase energy

True

T or F: velocity is not constant

false

The _______ the wavelength the _____ the energyg

smaller wavelength, higher energy

What can x-ray wavelength be measured by

Angstrom (A)

or

10^-10 meters

Energy and wavelength are

inversely proportional

as energy ________, wavelength ________

increases, decreases

Electromagnetic spectrum longest to shortest wavelength

radio waves, microwaves, infrared, visible light, UV, x-ray, gamma rays

Light

packets of energy called photons

Photons

atom of light

characteristics of photons

• smallest quantity of any type EM radiation

• bundle of energy (quantum)

• no charge, weight, or mass

• electric and magnetic fields

Visible light

• small part, center

• violet to red

• each color we see has diff wavelength

Visible light can be _______, ________, and ________.

refracted, reflected, absorbed

3 degrees of absorption

1. transparent

2. translucent

3. opaque

Transparent

light passes without interruption

Translucent

light passes, reduced intensity

Opaque

light completely absorbed

Gamma rays (γ)

• emitted by radioactive sources

• cause ionization

Gamma rays are used for

medical (therapeutic, diagnostic)

security

X-rays

• determines bones are broken, teeth have cavities

X-rays are used for

medical (therapeutic, diagnostic)

security

Ultra-violet (UV) light

• causes suntans, sunburn, cancer

UV lights are used for

sterilizing equipment

Infrared Light (IR)

IR goggles help firefighters, soldiers, home insulation experts

IR are used for

remote controls

Microwaves

• low energy, frequency

• long wavelength

Microwaves are used for

• microwaves

• ovens

• cellphone signals

Radio waves

• very low energy and frequency

• very long wavelengths

Radio waves are used for

MRI

radio transmission

tv

walkie talkie

GPS

weather radar

radar guns

Radio waves: visible light is identified by _________

wavelength

Radio is identified by _______

frequency

x-rays and gamma rays are identified by ______

energy

difference between x-rays and gamma rays

x-rays originate outside nucleus in electron shells

gamma rays originate inside nucleus

Visible light photons behave more like _____ than __________.

waves than particles

X-rays photons behave more like ________ than ______.

particles than waves

Which photons exhibit wave-particle duality of radioation

visible light and x-ray

Attenuation

absorption, scatter of radiation

causes reduction in x-ray intensity

Radioplaque

material that absorb x-rays

bone

Radiolucent

material x-rays easily penetrate

air, soft tissue

How are radiation and distance related

inversely proportional

As distance __________, radiation intensity ____________.

increases, decreases