Units, Physical Quantities and Vectors Flashcards

Flashcards on Units, Physical Quantities, and Vectors from a Medical Physics lecture.

Physics

Based on experimental observations and quantitative measurements.

Three fundamental quantities in mechanics

Length, mass, and time.

SI (Système International)

A set of standards for the fundamental quantities of science established in 1960.

Fundamental SI units of length, mass, and time

Meter, kilogram, and second.

Derived quantities

Variables that can be expressed as a mathematical combination of fundamental quantities.

Dimension

Denotes the physical nature of a quantity.

Units

Physical unit of a quantity.

Symbols for the dimensions of length, mass, and time

L, M, and T

Scalar Quantity

A quantity fully described by magnitude only.

Vector Quantity

A quantity fully described by both magnitude and direction.

Equality of Two Vectors

Must have the same magnitude and direction.

Negative of a Vector

Same magnitude but opposite direction.

Unit Vector

A dimensionless vector with a magnitude of 1, used to specify direction.