Physics

Definition of Physics

An experimental science studying motion, waves, light, electricity, magnetism, atoms, and nuclei.

Physics "Law"

A causal mathematical relation between variables inferred through reasoning.

Types of Measurements

Vectors and Scalars.

Velocity Vectors

Measurements with both Direction and Amount related to motion.

Displacement Vectors

Measurements with Direction and Amount related to change in position.

Mass Scalars

Measurement of Amount referring to an object's weight.

SI Units

Meters (m), Seconds (s), Kilograms (Kg), Mole (mol).

Scientific Notation

A method of expressing numbers as a product of a coefficient and a power of ten, typically in the form of _____ = a × 10^n, where 1 ≤ a < 10 and n is an integer. This notation is useful for simplifying calculations and representing very large or very small numbers.

Kinematics

The study of motion.

Point-like Particle

Represents the center of mass of an object in kinematics.

Reference Frame

Umbrella term for Reference Time and Reference Position.

Delta (Δ) Symbol

Indicates change in a value, e.g., Δv = v2 - v1.

Vector Representation

Vectors in one dimension must include direction, denoted by an arrow above the variable.

Time

A reading on a clock or time-measuring instrument.

Time Interval

The difference between two times, represented as Δt in equations.

Uniform Velocity

Velocity that does not change and is consistent throughout the reference frame.

Non-uniform Velocity

Velocity that changes throughout the reference frame, which can increase or decrease.

Position-versus-time graph

A graph where the slope represents velocity, commonly used in Kinematics.

Average Velocity

Calculated by dividing the change in displacement by the change in time (Δx/Δt).

Net Displacement

The sum of the components in the reference frame, considering direction.

Path Length

The sum of the magnitudes of the components, disregarding direction.

Acceleration

The rate of change of velocity of an object.

Average Acceleration

Found by dividing the change in velocity by the change in time (Δv/Δt).

Instantaneous Velocity

The velocity of an object at a specific instant in time.

Velocity-versus-time graph

A graph where the slope represents acceleration.

Air-resistance

A force that affects the rate of fall of objects, causing lighter objects like feathers to fall slower than heavier objects like bowling balls.

SUVAT equations

A set of equations used to solve problems involving acceleration and projectile motion.

Projectile Motion

Motion in two directions, typically analyzed through vertical and horizontal properties.

Range Formula

(v₀² * sin(2θ)) / g

Free Body Diagram

A diagram that shows all of the forces currently acting on an object.

Net Force

The total force on a system resulting from multiple interactions, calculated as the vector sum of all acting forces.

First Law (Law of Inertia)

An object at rest stays at rest, and an object in motion stays in motion unless acted upon by a net external force.

Second Law (Law of Acceleration)

The acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass (F = ma).

Third Law (Action and Reaction)

For every action, there is an equal and opposite reaction.

Newton (N)

The unit of measurement for force, equivalent to Kgms^-2.

Static Friction

The type of friction that prevents an object from starting to slide.

Kinetic Friction

The type of friction that opposes the motion of an object that is sliding.

Coefficient of Friction

μ

Uniform Circular Motion

Motion of an object traveling at a constant speed along a circular path while changing its velocity direction.

Radial Acceleration

The acceleration that causes the change in direction of an object in circular motion, dependent on speed and radius.

Formula for Velocity (V)

V = (2πr)/T, where r is the radius and T is the period of motion.

Frequency (f)

The number of complete revolutions per unit time, defined as f = 1/T.

Radial Acceleration Formula

aR = v²/r, which can also be expressed as aR = (4π²r)/T².

Centripetal Net Force

The net force acting on an object in circular motion, directed towards the center of the circle, responsible for maintaining circular motion.

Freefall

A condition in which objects perceive themselves as weightless due to the inability to counteract the force of gravity.

Orbital motion

The motion of an object in freefall that maintains its path around another body, such as a planet or satellite.

Kepler’s Laws

A set of three laws that describe the motion of planets in their orbits around the sun.

Elliptical orbits

The shape of planetary orbits, which are ellipses with the sun located at one of the foci.

Equal area law

The principle that planets sweep out equal areas in equal times during their orbit.

Orbital period

The time it takes for a planet to complete one full orbit around the sun, which is related to the semi-major axis of the orbit.

Universal law of gravitation

A law that models the gravitational attraction between two objects with mass as a force acting between idealized point particles.

Linear Momentum

The total momentum of a system of moving objects, equal to the vector sum of the individual linear momenta.

Impulse

The change in momentum imparted to an object by a force acting over a time interval.

System Energy

A system of one or more objects has energy due to their motion, interactions, and internal composition.

Kinetic Energy

Energy due to the motion of an object.

Internal Energy

Energy due to temperature and atomic structure of a system.

Gravitational Potential Energy

Energy due to the separation between an object and the Earth.

Elastic Potential Energy

Energy due to the deformation of a spring.

Work-Energy Equation

Ei + W (ΔE) = Ef, describing how external work changes a system's energy.