Physics 100 Midterm #1 Key Vocabulary and Concepts

Vocabulary and concept flashcards based on Physics 100 Midterm #1 questions and diagrams.

Theory (in science)

A synthesis of a large body of well-tested knowledge.

Scientific Speculation

A statement declaring that certain phenomena, such as regions beneath Earth's crust, will always be beyond the reach of scientific investigation.

First Introduction of Inertia

The historical achievement attributed to Galileo, who was the first scientist to introduce the concept of inertia.

Horizontal Speed of Falling Package

The horizontal component of velocity of an object dropped from a truck moving at $30\,\text{m/s}$, which remains about $30\,\text{m/s}$ just before impact when neglecting air resistance.

Newton's Law of Inertia

The principle stating that an object in motion continues moving indefinitely in a straight line unless acted upon by net opposing forces.

Kilogram

A standard unit of measurement used to quantify an object's mass.

Net Force

The overall resultant force acting on an object; for example, a $10\text{-N}$ falling object encountering $4\,\text{N}$ of air resistance experiences a net force of $6\,\text{N}$.

Curved Track Arrival Time

The physical situation where Ball C on a track with a lowered middle dip reaches the end first because it gains extra speed while rolling through the depression.

Automobile Acceleration Controls

Vehicle mechanisms capable of changing speed or direction, which include the gas pedal, brake pedal, and steering wheel.

Spiral Tube Trajectory

The straight-line path (Path B) taken by a pellet upon exiting a curved horizontal tube, as no further centripetal force acts on it after leaving the tube.

Tension Force

A pulling force that acts to stretch an object.

Zero Acceleration State with Air Resistance

The condition of terminal velocity reached first by the lighter individual when a light woman and heavy man jump simultaneously with identical parachutes.

Action and Reaction Forces

Paired interactive forces described by Newton's third law that are always exactly equal in magnitude and opposite in direction.

Gravitational Action-Reaction Pair

The equal gravitational force of $500\,\text{N}$ exerted by a person on Earth when attracted to Earth's center by a $500\text{-N}$ gravitational force.

Spring Scale Reading

The scale reading of $100\,\text{N}$ recorded by a spring scale connected via pulleys to two hanging $100\text{-N}$ weights.

Braking Kinetic Energy Transformation

The conversion of a moving automobile's kinetic energy into heat when brought to a stop by braking.

Gravitational Potential Energy Gain

The doubling of potential energy gain achieved when lifting an object to twice its original height (from $10\,\text{meters}$ to $20\,\text{meters}$).

Work Done by Gravity on Horizontal Motion

Zero work, because the force of gravity acts perpendicular ($90^\circ$) to the direction of horizontal motion.

Penetration Distance and Speed

The four-fold increase in penetration distance when firing an arrow at twice the speed of an identical arrow, as kinetic energy depends on speed squared.

Truck Stability on an Incline

The tipping condition where a vehicle (such as Truck C) tips over because its center of gravity falls outside its base of support.

Impulse

A physics quantity equal to force multiplied by time, which directly equals the change in momentum it produces.

Torque

A rotational force action acting on an object that tends to produce rotation.

Stability of the Leaning Tower of Pisa

The structural stability resulting from its center of gravity remaining located directly above a place of support.

Mechanical Equilibrium

The state of a system where both the resultant net forces and resultant net torques acting on it are zero.

Rolling Race Down an Incline

The race between a ring and a disk where the disk reaches the bottom first because of its smaller rotational inertia relative to its mass.

Horizontal Broom Balance Point

The balance point where the center of gravity lies closer to the bristles end, making the bristles piece heavier when cut at that point.

Centrifugal Force

An apparent force experienced strictly by observers within a rotating reference frame.

Moment of Inertia Ranking

The ordering of rotational inertias from smallest to largest for objects of equal mass rotating about a central axis: B (solid cylinder), A (ring/shell), C (extended dumbbell shape).

Conservation of Angular Momentum

The physical law governing phenomena such as shrinking stars spinning faster, figure skaters spinning faster when pulling in limbs, and divers tucking during somersaults.

Turntable Crawl Angular Momentum

The system condition where crawling outward on a freely rotating turntable keeps overall angular momentum unchanged while reducing angular speed (RPMs).