Introduction to Physics: Physical Quantities and Measurements

Comprehensive vocabulary flashcards covering basic physics concepts, SI units, scientific notation, measurements, and errors.

Physical Quantities

Measurable properties or characteristics of matter and energy that can be directly measured or quantified using instruments.

Non-Physical Quantities

Abstract quantities that cannot be measured directly with instruments and are not related to the physical properties of matter and energy, such as happiness or justice.

Newton's Second Law of Motion

A physics law expressed by the formula $F=ma$, where $F$ is force ($\text{N}$), $m$ is mass ($\text{kg}$), and $a$ is acceleration ($\text{m/s}^2$).

Base Quantities

The seven fundamental physical quantities defined independently in the International System of Units (SI), including Length, Mass, Time, and Temperature.

Derived Quantities

Physical quantities, such as Area, Volume, and Force, that are formed by combinations of base quantities using mathematical relationships.

Exa (E)

An SI prefix representing a multiplier of $10^{18}$.

Nano (n)

An SI prefix representing a multiplier of $10^{-9}$.

Atto (a)

An SI prefix representing a multiplier of $10^{-18}$.

Scientific Notation

A method of expressing very large or very small numbers in the form $m \times 10^n$, where $m$ is a number between 1 and 10 and $n$ is an integer.

Scalar Quantities

Physical quantities that have only magnitude (amount) without direction, such as mass, time, and density.

Vector Quantities

Physical quantities that possess both magnitude and direction, such as displacement, velocity, acceleration, and force.

Head-to-Tail Rule

A graphical method used to combine two or more vectors to determine a single resultant vector (R).

Least Count (LC)

The smallest unit of measurement that a specific instrument can measure accurately.

Screw Gauge (Micrometer) Least Count

Calculated using the formula: $\text{LC} = \text{Pitch} \times (\text{Number of circular scale divisions})^{-1}$.

Vernier Calipers Least Count

Typically $0.1\text{ mm}$ ($0.01\text{ cm}$), calculated by dividing 1 Main Scale Division by the number of Vernier Scale Divisions.

Systematic Errors

Predictable, consistent errors in one direction often caused by improper calibration, zero error, or faulty equipment.

Random Errors

Unpredictable variations in measurements caused by human error, instrument sensitivity limitations, or environmental fluctuations.

Precision

A measure of how consistent or repeatable measurements are across multiple trials.

Accuracy

A measure of how close a specific measurement is to the true or correct value.

Significant Figures

The digits in a measurement that carry meaningful information about its accuracy, including all certain digits and the first uncertain (estimated) digit.

Significant Figure Rule: Leading Zeros

Zeros appearing before the first non-zero digit are not significant as they only serve as placeholders.

Significant Figure Rule: Trailing Zeros

Zeros after a decimal point are significant because they indicate measurement precision; zeros in whole numbers without a decimal are usually not significant.