Physics Lecture Notes: Fundamentals to Fluid Mechanics

Physics

An experimental science in which physicists seek patterns that relate the phenomena of nature.

Physical theories

The patterns that relate the phenomena of nature.

Physical law or principle

A very well established or widely used theory.

The International System (SI)

The most widely used system of units, including base units such as the meter, Kelvin, Ampere, and kilogram.

Tera (T)

A metric prefix representing a multiplication factor of $10^{12}$.

Nano (n)

A metric prefix representing a multiplication factor of $10^{-9}$.

Femto (f)

A metric prefix representing a multiplication factor of $10^{-15}$.

Dimensional Analysis

The practice of checking equations for consistency using fundamental dimensions: Mass [M], Time [T], and Length [L].

Significant Figures

The number of digits in a measurement that indicate its precision; more figures signify less uncertainty.

Scientific Notation

A way to write very large or small numbers in the general formula $a \times 10^{n}$, where $a$ is a number between $1$ and $10$ and $n$ is an integer.

Scalar quantity

A physical quantity described by a single number representing magnitude only.

Vector quantity

A physical quantity that has both a magnitude and a direction in space.

Kinematics

The study of motion describing how objects move (position, velocity, and acceleration) without considering forces.

Displacement

A vector quantity representing the straight-line distance and direction from a starting point to an ending point.

Average Velocity ($v_{avg}$)

The rate of change of displacement calculated as $\frac{\text{displacement}}{\text{time}}$ or $\frac{\triangle x}{\triangle t}$.

Instantaneous velocity

The velocity at a specific instant of time or point along a path, given by $v = \frac{dx}{dt}$.

Acceleration

The rate of change of velocity with time, measured in $m/s^{2}$; it is a vector quantity.

Dynamics

The study of motion that analyzes why objects move by considering forces, mass, and energy.

Force

A push or pull interaction between two objects or between an object and its environment.

Normal force ($\textbf{N}$)

A contact force exerted on an object by any surface it is in contact with, acting perpendicular to that surface.

Friction force ($\textbf{f}$)

A contact force exerted on an object by a surface that acts parallel to the surface and opposes sliding.

Tension force ($\textbf{T}$)

The pulling force exerted by a stretched rope or cord on an object to which it is attached.

Weight ($\textbf{w}$)

The gravitational force that the earth exerts on a body, calculated as $w = mg$.

Resultant force ($\textbf{R}$)

A single force that has the same effect on an object as all individual forces acting together; the vector sum of all forces.

Newton's First Law of Motion

Also known as the Law of Inertia, it states that a body acted on by no net force moves with constant velocity and zero acceleration.

Inertia

The tendency of an object to resist changes in its velocity, whether motion or motionless.

Newton's Second Law

States that the acceleration of an object is directly proportional to the net external force acting on it ($$ extstyle extstyle extstyle extstyle extstyle extstyle extstyle extstyle extstyle extstyle extstyle extstyle extstyle extstyle extstyle extstyle extstyle extstyle extstyle ext