Physics Fundamentals: Key Concepts Defined

Classified in Physics

Written on July 2, 2025 in English with a size of 5.35 KB

Core Concepts of Motion & Force

Motion: Change in position relative to a reference point.
Frame of Reference: A system for specifying the precise location of objects in space and time.
Displacement: The change in position of an object. Always includes direction.
Speed: The distance traveled divided by the time interval during which the motion occurs.
Velocity: The speed of an object in a particular direction.
Acceleration: The rate at which velocity changes.

Force: Any action that can change the state of motion of an object.
Friction: An unbalanced force that acts against an object's direction of motion.
Static Friction: The force that resists the initiation of sliding motion between two surfaces that are in contact at rest.
Kinetic Friction: The force that opposes the movement of two surfaces that are in contact and are moving over each other.
Inertia: The tendency of an object to resist a change in motion unless an outside force acts on the object.
Weight: A measure of the gravitational force exerted on an object.
Free Fall: The motion of a body when only the force of gravity is acting on the body.
Terminal Velocity: The constant velocity of a falling object when the force of air resistance is equal in magnitude to the gravitational force.
Projectile Motion: The curved path that an object follows when thrown, launched, or otherwise projected near the surface of Earth.
Momentum: A quantity defined as the product of an object's mass and velocity.

Work: The transfer of energy to an object by the application of a force that causes the object to move in the direction of the force.
Power: A quantity that measures the rate at which work is done or energy is transformed.
Energy: The capacity to do work.
Potential Energy: The energy that an object has because of its position, shape, or condition.
Kinetic Energy: The energy of an object due to the object's motion.
Mechanical Energy: The amount of work an object can do because of the object's kinetic and potential energy.
Efficiency: A quantity, usually expressed as a percentage, that measures the ratio of useful work output to work input.

Mechanical Advantage: A quantity that expresses how much a machine multiplies force or distance.
Simple Machines: One of the six basic types of machines, which are the basis for all other forms of machines.
Compound Machines: A machine made of more than one simple machine.

Sound Waves: A longitudinal wave caused by vibrations that travels through a material medium.
Pitch: A measure of how high or low a sound is perceived to be, depending on the frequency of the sound wave.
Infrasound: Slow vibrations with frequencies lower than 20 Hz.
Ultrasound: Any sound wave with frequencies higher than 20,000 Hz.
Resonance: A phenomenon that occurs when two objects naturally vibrate at the same frequency.
Sonar: A system that uses acoustic signals and echoes to determine the location of objects or to communicate.

Photons: A unit or quantum of light.
Intensity: The rate at which energy flows through a given area of space.
Radar: A system that uses reflected radio waves to determine the velocity and location of objects.
Light Rays: A line in space that matches the direction of the flow of radiant energy.
Virtual Image: An image from which light rays appear to diverge; cannot be projected on a screen.
Real Image: An image formed by the intersection of light rays; can be projected on a screen.
Lens: Refracts light waves such that they converge or diverge to create an image.
Magnification: The increase of an object's apparent size by using lenses or mirrors.
Prism: A system that consists of two or more plane surfaces of a transparent solid at an angle with each other.
Dispersion: The process of separating a wave into different frequencies into its individual component waves.

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