Exam 1 Terms

Question 1

Mathmatics is…

Answer 1

Logical truth constructed by human thought

Question 2

Axioms are

Answer 2

statements that are accepted to be true with out proof

Question 3

Theoretical physics is the human bridge between

Answer 3

observation and understanding

Question 4

Euclidean Geometry is when a triangles angles is always ___ and parallel lines remain ___ to infinity

Answer 4

• 180 degrees
• parallel

Question 5

Cartesian coordinates are

Answer 5

Triplet of real numbers representing its position along orthogonal axes

Question 6

Differential calculus is the study of

Answer 6

instantaneous rates of change

Question 7

Differential equations
characterize how

Answer 7

quantities change with respect to one another

Question 8

Euler’s number is

Answer 8

e = 2.71828

Question 9

Energy in physics represents

Answer 9

an entity’s capacity to do work or to create change
within its environment.

Question 10

Potential energy in physics represent

Answer 10

work that has yet to be done

Question 11

Noether’s Theorem is

Answer 11

realization, that conservation laws follow from invariances

Question 12

Particles are directed by ___ ___ law

Answer 12

Lorentz Force Law

Question 13

Radiation is the

Answer 13

nonlocal transfer of energy, from one location to another by particles and waves.

Question 14

Einstein’s Special Theory can be deduced from two postulates, namely

Answer 14

1. The laws of physics are identical for all observers in uniform motion.
2. The speed of light is a constant.

Question 15

What are the four fundamental forces?

Answer 15

• Gravity
• Electromagnetism
• Strong and weak nuclear forces

Question 16

electromagnetic spectrum energies from lowest to highest (7)

Answer 16

• Radio waves
• Microwaves
• Infrared
• Visible light
• Ultravilot
• Gamma rays

Question 17

Indeterminism states that

Answer 17

The dynamics of any system can be determined with perfect accuracy if enough info is provided

Question 18

Discretization states that

Answer 18

Only certain bound state energies are permitted

Question 19

Wave-particle Duality

Answer 19

-Em waves can sometimes behave like particles

-Classical particles (electrons) can sometimes show properties of waves

Question 20

Spin is when particles

Answer 20

carry intrinsic angular momentum

Question 21

A Photons Energy is directly proportional to its

Answer 21

frequency

Question 22

A Photons Energy is inversely proportional to its

Answer 22

wavelength

Question 23

• What does “conserved” mean
• What quantites are conserved

Answer 23

• Unchanging in time
• Energy, momentum and angular momentum

Question 24

Phosphors are substances that

Answer 24

Absorb energy from light of one wavelenght and relese that energy as light of a different wavelength in the visible spectrum

Question 25

Fluorescence are substances that

Answer 25

release visible light immediately (anyrhing that shines under a black light)

Question 26

Phosphorescence are substances that

Answer 26

Release energy as light over a extended duration (glowsticks)

Question 27

Atomic Physics Notations - Z - N - A

Answer 27

- Atomic number - Mass number - Different nuclei

Question 28

Define isotope - Same - Different

Answer 28

- Protons and electrons - Neutrons

Question 29

Isobars have the same number of

Answer 29

Atomic number (A)

Question 30

Isotones have the same number of

Answer 30

Neutrons (N)

Question 31

Isomes have the same ... but different ___

Answer 31

- Z, N, A - Energy states

Question 32

Electron capture happens in ___ rich nuclei

Answer 32

protein

Question 33

Explain electron capture

Answer 33

A proton in the nucleus is converted to a neutron, by absorbing an orbital electron

Question 34

Electron capture competes with ___ decay

Answer 34

Beta-plus

Question 35

Internal conversion competes with ___ ___ ___

Answer 35

Gamma ray emission

Question 36

Explain Internal Conversion

Answer 36

An excited nucleus might dexcite by releasing a gamma ray. Also migh kick an electron from the inner orbital

Question 37

What is "activity"

Answer 37

How many decays are occuring per unit time

Question 38

How are Z and N related for stable elements

Answer 38

Neutrons (N) increase relative to the number of protons (Z)

Question 39

Ionizing radiation is

Answer 39

High energy radiation that can remove electrons

Question 40

Non-ionizing radiation is

Answer 40

Low energy radiation the cant remove electrons

Question 41

linear attenuation coefficient is the

Answer 41

Fraction of photons removed from a monoenergetic beam. (rays per unit thickness)

Question 42

linear attenuation coefficient depends on (3)

Answer 42

- Incoming photon energy - Z of the attenuator - Density of attenuator

Question 43

mass attenuation coefficient is the

Answer 43

linear attenuation coeddicient divided by the density of the material

Question 44

mass attenuation coefficient is dependent on

Answer 44

The density of the absorber

Question 45

Define Homogeneous materials

Answer 45

materials that have a uniform composition throughout, meaning that their chemical composition and structure are the same at every point

Question 46

inhomogeneous materials are materials that have

Answer 46

non-uniform properties, such as density or mechanical properties

Question 47

Rayleigh (coherent) scatter characteristics (2)

Answer 47

- no energy transferred, -photon absorbed and emitted in slightly different direction

Question 48

Photoelectric effect - Depends on - Threshold photon energy

Answer 48

- Atomic number and energy - >10 MeV

Question 49

Define Photodisintegration

Answer 49

neutrons freed from nuclei of heavy metals in the collimator for high energy therapy beams

Question 50

Compton scattering - Depends on

Answer 50

- Electron density

Question 51

Pair production - Threshold energy - electron-positron annihilation

Answer 51

- 0.511 MeV each - Creats two annihilation photons traveling in opposite directions

Question 52

Which interaction mechanism is most likely in tissue in therapeutic energy range?

Answer 52

Compton effect

Question 53

What is the "heel effect"

Answer 53

When there is lower field intensity towards the anode compared to the cathode

Question 54

Diagnostic x-ray filters - what are they?

Answer 54

Metal sheets that reduce the intensity of low energy xrays

Question 55

Output dose depends on (3)

Answer 55

- Tube energy - Tuber current - Filament current

Question 56

Small focal spot - Pro - Con

Answer 56

- Sharp image quality - Bad heat dissipation

Question 57

Large focal spot - Pro - Con

Answer 57

- Poor image quality - Good heat dissipation

Question 58

Bremsstrahlung - Definition - Direction depends on what? - Created by

Answer 58

- electromagnetic radiation emitted when a charged particle, like an electron, rapidly decelerates while passing through matter - energy - Interactions with the electric fiels of an atomic nucleus

Question 59

As frequency increases, wavelength ___

Answer 59

Decreases

Question 60

Define decay constant

Answer 60

The probability of a radioactive atom deacying per unit of time

Question 61

Define mean life

Answer 61

the average time an unstable atom or nucleus survives before it decays.