DMS 110 - Ultrasound Physics I: Chapter 1 The Basics

Vocabulary terms covering basic math concepts, relationships, units, and scientific notation as they apply to Ultrasound Physics.

Horizontal axis

The x-axis of a graph, represented as a green line in diagrams.

Vertical axis

The y-axis of a graph, represented as a red line in diagrams.

Related or Proportional

A relationship where two items are associated with one another.

Unrelated

A relationship where two items are not associated with one another.

Directly Related or Directly Proportional

Two items associated such that as one item increases, the other increases, or as one decreases, the other decreases.

Inversely Related or Inversely Proportional

Two items associated such that as one item increases, the other item decreases, or vice versa.

Reciprocal Relationship

A special form of inverse relationship where the result of multiplying two numbers is $1$. When one number increases, the other decreases.

Factors

The numbers being multiplied in the equation $\text{factor (a)} \times \text{factor (b)} = \text{product (c)}$; they are directly related to the product.

Product

The result of multiplication which has a direct relationship with its factors.

Quotient

The result of division, which is directly related to the numerator and inversely related to the denominator.

Numerator

The value above the division bar; in the formula $a = b/c$, it is variable $b$.

Denominator

The value below the division bar; in the formula $a = b/c$, it is variable $c$.

Units for Area

Measurements typically expressed as length squared, such as $\text{inches}^2$.

Units for Volume

Measurements typically expressed as length cubed, such as $\text{inches}^3$.

Increase by a factor of…

A phrase meaning to multiply by the number given; for example, an increase by a factor of $5$ means it is $5$ times larger.

Decrease by a factor of…

A phrase meaning to divide by the number given; for example, a decrease by a factor of $4$ means the value becomes $\frac{1}{4}$ of the original.

Unitless number

A number that is followed by a percentage.

Metric System base units

The units representing $10^0$, which include meter, second, and Hertz.

Complementary Metric Units

Pairs of units used in ultrasound, such as Megahertz (millions of cycles) and microseconds (millionths of seconds).

Scientific Notation

A shorthand method for writing very large or very small numbers, keeping the primary number between $1$ and $10$ multiplied by a power of $10$.

Positive exponent (Scientific Notation)

Indicates a number with a value greater than $10$.

Negative exponent (Scientific Notation)

Indicates a number with a value less than $1$.

Power

A shorthand for taking a number and multiplying it by itself a specific number of times; for example, $2^8 = 256$.