Key Physics Concepts and Formulas

Displacement

Change in position in a specific direction (vector). Unit: meters (m)

Position

A point relative to an origin or reference point. Unit: meters (m)

Time

The ongoing progression of events. Unit: seconds (s)

Velocity

Speed in a specific direction (vector). Unit: m/s. Formula: v = Δx/Δt

Speed

How fast something is moving (scalar). Unit: m/s. Formula: s = d/t

Vector

A quantity with both magnitude and direction (e.g., velocity, force)

Scalar

A quantity with only magnitude (e.g., speed, mass, time)

Acceleration

The rate of change of velocity. Unit: m/s². Formula: a = Δv/Δt

Newton's 1st Law

An object stays at rest or in motion unless acted on by a net external force (Law of Inertia)

Newton's 2nd Law

The net force on an object equals mass times acceleration. Formula: F = ma

Newton's 3rd Law

For every action, there is an equal and opposite reaction

Friction

A force that resists motion between two surfaces in contact

Coefficient of Friction (μ)

Ratio of frictional force to normal force. Unit: none. Formula: f = μN

Sliding Friction

Resistance between two surfaces sliding past each other

Static Friction

Resistance to the start of motion between two objects

Rolling Friction

Resistance when an object rolls over a surface

Fluid Friction

Resistance in fluids or air (also known as drag)

Weight

Force due to gravity on an object. Unit: N. Formula: W = mg

Mass

Amount of matter in an object. Unit: kilograms (kg)

Gravity (g)

Acceleration due to gravity (~9.8 m/s² on Earth)

Interval

A span or gap between two values, often for time or position

Kilo-

Prefix meaning 1,000 (10³)

Hecto-

Prefix meaning 100 (10²)

Deca-

Prefix meaning 10 (10¹)

Deci-

Prefix meaning 0.1 (10⁻¹)

Centi-

Prefix meaning 0.01 (10⁻²)

Milli-

Prefix meaning 0.001 (10⁻³)

Dimensional Analysis

Method to convert units using conversion factors

Significant Digits

Digits in a measurement that are known with certainty plus one estimated digit

Force

A push or pull on an object. Unit: newtons (N). Formula: F = ma

Speed Formula

s = d/t

Velocity Formula

v = Δx/Δt

Acceleration Formula

a = Δv/Δt

Force Formula

F = ma

Weight Formula

W = mg

Friction Formula

f = μN