Introductory Physics Concepts and History

Vocabulary flashcards covering foundational physics concepts, history of science, scientific laws, unit conventions, and gravitation.

Isaac Newton (Royal Mint Role)

The scientist who served at the Royal Mint and introduced the ridges (grooves) along the edges of coins to deter coin clipping.

Scientific Notation of 547 Million

The mathematical representation of 547,000,000 expressed in standard scientific notation as $5.47 \times 10^8$.

Physical Laws

Fundamental scientific statements and principles that describe observed, reproducible patterns in Nature.

Scientific Method

A systematic approach to understanding nature based on observations, questions, hypotheses, and controlled experiments.

Galileo Galilei

One of the earliest scientists to recognize and champion the essential role of observation and experimentation in scientific investigation.

Classical Physics Speed Assumption

The fundamental premise in Classical Physics that all motion occurs at speeds very small compared to the speed of light, specifically less than $1\%$ of $c$.

Marie Curie

The only scientist to win Nobel Prizes in two distinct scientific disciplines: Physics and Chemistry.

Niels Bohr

The physicist who performed foundational research on the structure of atoms, leading to the development of Quantum Mechanics in the early 1900s.

SI Unit

A unit belonging to the International System of Units (Système International)—including seconds ($\text{s}$), meters ($\text{m}$), kilograms ($\text{kg}$), and amperes ($\text{A}$)—which excludes non-metric imperial units such as pounds ($\text{lb}$).

Inverse-Square Law of Gravity

The physical principle that gravitational force varies inversely with the square of the distance: if orbital distance increases by a factor of $2.85$, gravitational attraction decreases by $(2.85)^2 = 8.12$ times.

Newton's Second Law of Motion

The law stating that the acceleration of an object is directly proportional to the net force applied and inversely proportional to its mass ($a = \frac{F}{m}$).

Newton's Third Law Misconception (Action-Reaction)

The erroneous claim that action and reaction forces cancel to yield zero net force, debunked by the fact that the two forces always act on different objects.

Direction "Up"

A directional vector defined relative to a celestial body's gravity as pointing radially outward, directly away from the center of the body (such as Earth or the Moon).

Radial Separation Distance ($R$)

In Newton's Universal Law of Gravity ($F_{\text{grav}} = \frac{G M_1 M_2}{R^2}$), the variable $R$ represents the distance between the centers of the two interacting masses.

Apparent Weightlessness

The sensation experienced by astronauts in orbit (such as aboard the ISS) because both the spacecraft and occupants are in continuous free-fall around Earth.

Earth-Moon Gravitational Force Pair

A mutual gravitational interaction governed by Newton's Third Law, where the pull Earth exerts on the Moon is equal in magnitude and opposite in direction to the pull the Moon exerts on Earth.

Free-Fall Acceleration at Peak

The constant downward acceleration ($32\,\text{ft/s}^2$ or $9.8\,\text{m/s}^2$ on Earth) experienced by a projectile under the sole influence of gravity, which remains constant even at the apex where vertical velocity momentarily reaches zero.

Shooting Star (Meteor)

A piece of icy or rocky interplanetary debris that burns up and vaporizes upon entry into Earth's atmosphere, creating a streak of light rather than being an actual star.