Topic Cluster

Classical Mechanics

Forces, energy, momentum and motion — the core of classical physics: Newton’s laws, work and energy, collisions, rotation and everyday mechanics.

Classical Mechanics

Impulse Formula (J = FΔt): How to Calculate Impulse

The impulse formula is J = FΔt, and it also equals the change in momentum. Work through 7 solved examples, learn to read impulse off a force-time graph, and see the four mistakes that cost the most marks.

15 min read

Classical Mechanics

How to Solve Physics Problems: A 6-Step Framework

Most physics problems break down at the setup, not the algebra. This six-step framework covers translating the question, drawing it, choosing the principle, rearranging, substituting in SI units and checking the answer, with six fully worked examples.

19 min read

Classical Mechanics

SI Units of Measurement in Physics

A complete reference to SI units in physics: the seven base units, how each is now defined by a constant of nature, the derived units and prefixes built from them, and how to convert without losing marks.

16 min read

Classical Mechanics

Physics Constants: Values, Units and Where to Use Them

A complete reference to the physics constants used in school and first-year university physics, with exact CODATA 2022 values, SI units and worked examples. Covers g, c, h, G, R, the Coulomb constant and the speed of sound, and explains which are exact and which are measured.

16 min read

Classical Mechanics

What Is Capacitance? C = Q/V and Energy Stored

Capacitance is the charge a component stores per volt, C = Q/V, measured in farads. This guide covers the formula, the parallel-plate equation, the energy stored in a capacitor, dielectrics, common misconceptions and seven worked problems.

14 min read

Classical Mechanics

Drag Force: Formula, Cd Values and Examples

Drag force is the resistance a fluid exerts on anything moving through it, from cars and cyclists to footballs and ships. This guide covers the drag equation, drag coefficients for nine common shapes, and seven worked examples.

18 min read

Classical Mechanics

Angular Velocity: Formula, Units and Examples

Angular velocity measures how fast something rotates, in radians per second. This guide covers the formula, the rpm to rad/s conversion, real examples and seven worked problems.

14 min read

Classical Mechanics

Moment of Inertia: Formula for Common Shapes

Moment of inertia measures how strongly an object resists a change in its spin about a chosen axis. This guide gives the formula, a table for nine common shapes, the parallel axis theorem, eight worked problems and the four mistakes that cost exam marks.

16 min read

Classical Mechanics

Spring Constant (k = F/x): Formula & Examples

The spring constant k measures a spring's stiffness in newtons per metre. Learn how to measure k from a force-extension graph, see typical values from slinky to car spring, and try the interactive lab and calculator.

15 min read

Classical Mechanics

Center of Mass: Formula, Examples & How to Find It

Center of mass is the mass-weighted average position of a system — the point where all its mass acts as one. Learn the formula, six worked examples, and how to find it.

13 min read

Classical Mechanics

Weight on Other Planets: Moon, Mars & More

Your weight changes from world to world even though your mass never does. Learn the W = mg formula and see what you'd weigh on the Moon, Mars, Jupiter and beyond.

13 min read

Classical Mechanics

The Pendulum Period Formula

A pendulum's period depends on just two things: length and gravity — mass never matters. Learn the T = 2π sqrt(L/g) formula, what changes on the Moon, and how to solve exam problems step by step.

14 min read

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