PHY112 Geometrical Optics and Mechanics - Flashcards (100 VOCABULARY entries)

100 vocabulary-style flashcards drawn from the lecture notes on measurements, SI units, prefixes, derived/pseudo units, unit conversions, and dimensional analysis.

Measurements

The process of describing natural phenomena using defined standards, which should be readily accessible, reliable, reproducible, and time-stable.

Standard

A reference quantity with defined properties used to measure other quantities.

Accessibility (in standards)

Standards that can be obtained and used by anyone, anywhere.

Reliability (in standards)

The property that a standard can be measured reliably across trials.

Reproducibility

The ability for different users to obtain the same result when applying the standard.

Time-stability

Standards should not change over time.

Fundamental quantity

Base quantities from which other quantities are derived (e.g., Length, Mass, Time).

Length (L)

A fundamental quantity representing distance; symbolized by L.

Mass (M)

A fundamental quantity representing the amount of matter; symbolized by M.

Time (T)

A fundamental quantity representing duration; symbolized by T.

Temperature

A fundamental quantity not used in mechanics as a primary quantity in these notes.

Electric current

A fundamental quantity not used as a core mechanics quantity in these notes.

Luminous intensity

A fundamental quantity not used as a core mechanics quantity in these notes.

Amount of substance

A fundamental quantity not used as a core mechanics quantity in these notes.

SI system

International System of Units; universally used, with base units metre, kilogram, second.

Metre

Base unit of length in SI, symbol m.

Kilogram

Base unit of mass in SI, symbol kg.

Second

Base unit of time in SI, symbol s.

Prefix

A symbol attached to a unit to denote multiplication by a power of ten.

Prefix abbreviation

The short form used to denote the multiplier (e.g., k for kilo, M for mega, T for tera).

Prefix name

The spelling name of the multiplier (e.g., kilo, mega, nano).

Tera

Prefix meaning 10^12.

Giga

Prefix meaning 10^9.

Mega

Prefix meaning 10^6.

Kilo

Prefix meaning 10^3.

Centi

Prefix meaning 10^-2.

Milli

Prefix meaning 10^-3.

Micro

Prefix meaning 10^-6.

Nano

Prefix meaning 10^-9.

Pico

Prefix meaning 10^-12.

Femto

Prefix meaning 10^-15.

Derived quantity

A quantity expressed in terms of fundamental quantities (e.g., Volume).

Volume

A derived quantity; volume = length × length × length (L^3).

Pseudo unit

Non-SI unit used to express a quantity, e.g., Newton (N) for force.

Newton

A pseudo unit for force; 1 N = 1 kg·m·s^-2.

Force

A derived quantity; in SI units, N (kg·m·s^-2).

SI unit

Units defined by the SI system (base or derived).

Conversion

Process of changing a quantity from one unit to another without changing the value.

Intra-system conversion

Converting within the same unit system (e.g., within SI prefixes).

Inter-system conversion

Converting between different unit systems (e.g., SI to imperial).

Prefix-to-prefix conversion

Changing from one prefix to another within the same system.

System-to-system conversion

Converting units across different unit systems.

Relationship factor

Multiplier used to relate two units in a conversion.

Dimension

The physical nature of a quantity, denoted by symbols in brackets, e.g., [Length], [Mass], [Time].

Brackets notation

[Q] indicates the dimensions of a physical quantity Q.

Dimension of Length

L.

Dimension of Mass

M.

Dimension of Time

T.

Volume dimension

L^3.

Speed dimension

LT^-1.

Force dimension

MLT^-2.

Dimensional consistency

In a valid equation, both sides must have the same dimensions.

Dimensionally homogeneous

An equation where every term has the same dimensions.

Frequency

Number of cycles per unit time; dimension T^-1.

Dimensional correctness

A relation is correct only if both sides have the same dimensions.

Left-hand side (LHS)

The left side of an equation, checked for dimensional consistency with the right-hand side.

Right-hand side (RHS)

The right side of an equation, checked for dimensional consistency with the left-hand side.

Dimension analysis example

A demonstration of checking equations for dimensional consistency.

A dimension

The dimension of a constant A in an equation like x = At + Bt^2; [A] = L T^-1.

B dimension

The dimension of a constant B in x = At + Bt^2; [B] = L T^-2.

Final velocity

v; dimension LT^-1.

Initial velocity

u; dimension LT^-1.

Acceleration

a; dimension LT^-2.

Time variable

t; dimension T.

k1 (dimensionless constant)

A dimensionless constant appearing in velocity-like relationships.

k2 (dimensionless constant)

A second dimensionless constant in time-velocity relations.

Position x

Distance along a line; dimension L.

A (in x = At + Bt^2)

Constant with dimension L T^-1.

B (in x = At + Bt^2)

Constant with dimension L T^-2.

Gravity g

Acceleration due to gravity; dimension L T^-2.

Height h

Vertical distance; dimension L.

Velocity v

Rate of change of position; dimension L T^-1.

Energy

Capacity to perform work; dimension M L^2 T^-2.

Angular momentum

L; dimension M L^2 T^-1.

Angular velocity

ω; dimension T^-1.

Density

Mass per unit volume; dimension M L^-3.

Area

Two-dimensional measure; dimension L^2.

Pressure

Force per unit area; dimension M L^-1 T^-2.

Velocity (redefinition)

Another term for the rate of change of displacement; same as v; dimension L T^-1.

Displacement

Change in position; dimension L.

Time interval

A duration; dimension T.

Mass (revisited)

Quantity of matter; dimension M.

Length unit (SI base)

The metre (m), base unit for length in SI.

Time unit (SI base)

The second (s), base unit for time in SI.

Mass unit (SI base)

The kilogram (kg), base unit for mass in SI.

1 mile (mi)

Unit of length; 1 mi equals 5280 feet.

1 foot (ft)

Unit of length; equals 12 inches.

1 inch (in)

Unit of length; equals 2.54 cm.

1 centimeter (cm)

Unit of length; equals 0.01 m.

1 meter (m)

SI base unit of length; equals 100 cm.

1 centimeter in meters

0.01 m.

1 liter in cubic centimeters

1 L = 1000 cm^3 (for volume in common usage).

1 hour (h)

Unit of time; equals 60 minutes.

1 minute (min)

Unit of time; equals 60 seconds.

1 second (s)

SI base unit of time.

1 millisecond (ms)

0.001 s.

1 microsecond (µs)

0.000001 s.

1 nanosecond (ns)

0.000000001 s.

1 kilometer (km)

1000 meters.

1 liter (L)

Volume unit; 1 L = 1000 cm^3.