The Journal

All articles

Every piece we've published, sorted by date. Each ends with worked problems and a FAQ.

Distance vs displacement diagram showing path length versus straight-line change in position

Distance vs Displacement Explained

Distance vs displacement explained simply: distance is the total path you cover, while displacement is your straight-line change in position. Includes the formula, a comparison table, worked problems and FAQs.

11 min read

Classical Mechanics

What Is Terminal Velocity?

Terminal velocity is the steady top speed a falling object reaches when air drag balances its weight. Learn the formula, see worked examples from skydivers to raindrops, and try an interactive lab.

13 min read

Kinematics

What Are the SUVAT Equations?

A clear guide to the SUVAT equations — the five equations of motion for constant acceleration. Includes the velocity–time graph derivation, worked examples, common mistakes and an interactive simulation.

13 min read

Work done in physics diagram showing force, displacement and the W = F d cos θ formula

Classical Mechanics

What Is Work Done in Physics?

Work done in physics is the energy a force transfers when it moves an object. This guide explains the W = F d cos θ formula with real examples, seven worked problems and an interactive lab.

16 min read

Ohm's law featured image showing the formula V = IR linking voltage, current and resistance

Electromagnetism

What Is Ohm’s Law?

Ohm's law links voltage, current and resistance through V = IR. Master all three formulas with worked examples, an interactive circuit lab and the misconceptions that trip students up.

15 min read

Acceleration in physics shown on a velocity–time graph where the slope equals a = Δv/Δt

Kinematics

What Is Acceleration in Physics?

Acceleration is the rate at which velocity changes, measured in m/s². Learn the a = Δv/Δt formula, see real-world examples and try the interactive lab.

12 min read

Doppler effect diagram showing sound waves compressed ahead of a moving ambulance and stretched behind it

Waves & Optics

What Is the Doppler Effect?

The Doppler effect is the change in a wave's observed frequency when the source and observer move relative to each other. Learn the formula, real examples from sirens to redshift, and try the interactive lab.

11 min read

Coulomb's law diagram showing the electric force between two point charges with the formula F = kq1q2/r2

Electromagnetism

What Is Coulomb’s Law?

Coulomb's law gives the force between two electric charges: F = kq₁q₂/r². Learn the formula and the value of k, work through seven examples, and test it all in an interactive lab.

14 min read

Special relativity light clock diagram showing time dilation at near light speed

Modern Physics

What Is Special Relativity?

Special relativity explains how time, length and energy change near the speed of light. Master Einstein's two postulates, the key formulas and the twin paradox — with worked examples.

16 min read

Frequency formula f = 1/T shown on a wave diagram measuring cycles per second in hertz

Waves & Optics

What Is the Frequency Formula?

The frequency formula, f = 1/T, gives the number of cycles per second in hertz. This guide explains how to calculate frequency from period, wavelength, and wave speed, with worked examples and the common mistakes to avoid.

10 min read

Velocity vs speed diagram: a directional velocity vector beside a scalar speed value in circular motion

Kinematics

Velocity vs Speed: What’s the Difference?

Speed is a scalar and velocity is a vector — that one difference is why average velocity can be zero on a round trip while you still cover real distance. Here's the full breakdown with examples, worked problems and an interactive demo.

13 min read

Kinetic energy formula KE = ½mv² illustrated with a speeding car and energy bars

Classical Mechanics

The Kinetic Energy Formula Explained

The kinetic energy formula KE = ½mv² explained in plain English — with units, the work–energy theorem, real-world examples and seven worked problems.

11 min read

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