Physics EXAM 1

The ability to do work

Energy

Anything with Mass

Matter

Matter occupies

Space

Matter has ___ measured in kg

Mass

Smallest unit of matter

Atom

Mass is the amount of

Matter

The force that keeps an electron in orbit is

Centripetal force

The force that causes an electron to travel straight and leave the atom is

Centrifugal force

Formula for Mass and energy equivalence

E= mc^2

Energy is measured in

Joules

Formula for speed of light in a vacuum

C= 3 x 10^8 m/s

Energy is the ability to do

work

Photon energy is measured in

eV

The ability to do work by virtue of position

potential energy

The energy of motion, rasing the book, falling book

Kinetic energy

The energy released by a chemical reaction

Chemical energy

Unit of thermal (heat) energy

Calorie

Energy of motion at the atomic level

Thermal energy

The amount of heat necessary to raise the temp of 1 g of water by 1 degree celsius is

1 calorie

3 ways thermal energy is transferred

Conduction, Convection, Radiation

Transfer of heat by direct or indirect contact is via

Conduction

Transfer of heat through a fluid or gas by molecular motion

Convection

Hot molecules rising and cold ones moving in to take their place is an example of

Convection

What transfers heat in a vacuum?

Thermal radiation

How does heat leave the xray tube housing to the surrounding air

Thermal radiation

Heat leaves the tube envelope to the insulating oil via

Conduction

Heat leaves from the oil to tube housing via

Convection

Which method is the primary cooling mechanism for the xray tube

Thermal radiation

the result of the movement of electrons

Electrical energy

Waves that act like a particle, produced by motion of electrically charged particles

Electromagnetic radiation

EM energy travels in

Waves

What is the smallest quantity of any type of electromagnetic energy

Photon

Small bundle of energy, also called a quantum.

Photon

Photons travel through space at the speed of

Light

Photons are waves measured in

Meters

The total amount of energy in an isolated system remains constant is what law

Law of Conservation of energy

A consequence of the law of conservation

Energy cannot be created or destroyed

Velocity =

Speed

Change in velocity =

Acceleration

Newton’s three laws of motion

Inertia, Force, Action/Reaction

Formula for force

F = m X a

How is force used in the xray process? The mass is the _____ and acceleration is set by ____

Electron and kVp

Electrons push on the anode and the anode pushes back, the reaction gives

Heat and EM radiation

The greater the velocity, the greater the

Momentum

Formula to calculate momentum

Mass x velocity

Formula for Work

Force x Distance

Force applied to an object times the distance

Work

The rate of doing work

Power

Formula for Power

Volt x current

When you use your force to push a box over a distance, this is

Work

SI unit for work is

Joule

Unit of power

Watt (W)

Work over time is equal to

Power

What makes up the nucleus

Protons and neutrons

How fast do photons travel through space

At the speed of light

Waves measured in meters

Photons

Smallest quantity of EM energy

Photon

what energy is light a form of

EM energy

Same velocity unless acted upon by an external force

Law of inertia

As you may recall the x-ray process is very inefficient, 99 % heat and 1% x-ray.  Which of the 3 ways that heat may be transferred  (radiation, convection or conduction) would occur in the oil that surrounds the exterior of the x-ray tube?

Convection

On the EM spectrum, a shorter wavelength represents ______ energy.

Higher

Which of Newton's Laws of motion:

•       Law of Inertia

•       F=ma

•      Equal and Opposite

would describe an electron sitting in the space charge cloud waiting to go over to the anode?

Law of inertia

Another way to write ten raised to the negative third, 10^-3, is ______.

1/1000 and 0.001

During characteristic x-ray production, the incident electron transfers a portion of its kinetic energy to the k-schell electron.

Which law is demonstrated in this scenario?

Conservation of momentum

The prefix "kilo" means ________

1000 and 10³

The unit of x-ray wavelength is the ______.

meters

300 ms = ?s

1. 3.0

2. 0.3

3. 30

0.3

I am using 10 mAs on a 200mA small focal spot. What is my exposure time in ms?

50

What is Newton’s 1st law

An object at rest will remain at rest unless acted upon by an external force

Xrays generated at a higher kVp have ____ wavelength, ____ frequency, and ____ energy

Shorter, higher, higher

Which of the following has a constant value for all EM radiation?

1. Wavelength

2. Frequency

3. Mass

4. Origin

5. Velocity

Velocity

How many protons are needed to create an oxygen atom

8

Difference between a photon of light and a photon of xray is their energy level

Photon energy difference, xray photons have higher energy and shorter wavelength)

Invisible, travel at the speed of light, can travel through a vacuum, obey inverse square law, can be absorbed, travel in sine waves

Electromagnetic radiation characteristics

Reduction in intensity of electromagnetic radiation due to absorption

Attenuation

Smooth repetitive oscillation that represents waves mathematically

Sine wave

Variation of displacement from center position in a wave

Amplitude

Highest point of a wave

Crest

Lowest point of a wave

Trough

Distance between two successive crests or troughs

Wavelength

Number of waves passing a given point per unit time

Frequency

Unit of wavelength

Meter

Unit of frequency

Hertz

Unit of wave velocity

Meters per second

Wavelength and frequency relationship where one increases as the other decreases

Inversely proportional relationship

Order from longest to shortest wavelength (and lowest to highest frequency)

radio waves, microwaves, visible light, gamma rays

Higher kVp produces shorter wavelength, higher frequency, and higher energy xrays

Effect of increasing kVp

Constant value for all electromagnetic radiation

Velocity (speed of light)

Some electromagnetic radiation has enough energy to remove electrons from atoms

Ionizing radiation

Process of removing or adding electrons to an atom

Ionization

Methods of ionization include thermal action, electron collision, light interaction, and shortwave electromagnetic exposure

Methods of ionization

Flow of electrons

Electricity

Smallest unit of electric charge

Electron

Functional unit used to measure electric charge

Coulomb

Equivalent number of electron charges in one coulomb

6 × 10¹⁸ electrons

Study of electrical charges at rest

Electrostatics

Unlike charges attract and like charges repel

Law of electrostatic attraction and repulsion

Force between two charges directly proportional to product of magnitudes and inversely proportional to square of distance

Coulomb’s law

Charges reside on the external surface of conductors

Law of distribution

Charges concentrate at areas with greatest curvature

Law of concentration