Physics Chapter 1: Radiologic Units and Motion

Flashcards covering radiologic units (SI and British), measurement systems, and the fundamental equations of motion including velocity and acceleration.

Air kerma ($Gy_a$)

The International System (SI) unit used to measure radiation in the air.

Gray ($Gy$)

The International System (SI) unit for absorbed dose.

Sievert (Sv)

The International System (SI) unit for dose equivalent.

Becquerel (Bq)

The International System (SI) unit for radioactivity.

Second (s)

The base unit of time, defined by the vibrations of cesium atoms in an atomic clock.

MKS System

The International System (Le Système International d'Unités), which is an extension of the meter, kilogram, and second system.

CGS System

A system of units based on the centimeter, gram, and second.

British System

A system of units that utilizes the foot ($ft$), pound ($lb$), and second ($s$).

Derived Units

Units such as mass density ($\text{kg/m}^3$) or pressure ($\text{N/m}^2$) that are formed from combinations of base units.

Volume ($V$)

The amount of space an object occupies, calculated as $V = \text{length} \times \text{width} \times \text{height}$.

Mass Density ($D$)

The mass per unit volume of an object, defined by the formula $D = \frac{\text{mass}}{\text{volume}}$.

Magnification ($M$)

The ratio of the source to image receptor distance ($\text{SID}$) to the source to object distance ($\text{SOD}$).

Velocity ($v$)

The rate of change of an object's position with time, calculated using the formula $v = \frac{d}{t}$, where $d$ is distance and $t$ is time.

Average Velocity ($\bar{v}$)

The mean of the initial velocity ($v_0$) and final velocity ($v_f$), represented by the formula $\bar{v} = \frac{v_0 + v_f}{2}$.

Velocity of light ($c$)

A constant value equal to $3 \times 10^8\text{ m/s}$, or approximately $669\text{ million miles in 1 hour}$.

Acceleration ($a$)

The rate of change of velocity with time, defined by the equation $a = \frac{v_f - v_0}{t}$ and expressed in units of $\text{m/s}^2$.