Mechanics

Kinematics · Forces and momentum · Work and energy

Linked Motion Graphs

Drag any one of the three graphs and watch the other two redraw with the object.

A.1 Kinematics

Projectile Launcher

Fire at any speed and angle, with the no-drag path left behind for comparison.

A.1 Kinematics

Collisions

No collision formula anywhere: the two bodies simply push each other while they touch.

A.2 Forces and momentum

The Inclined Plane

Tilt it until it goes. The gauge fills only as far as it needs to, then snaps down to what sliding takes.

A.2 Forces and momentum

The Circular Motion Rig

Three ways of being pulled towards a centre: a string, a banked road, and a loop that lets go at the top.

A.2 Forces and momentum

Work

Work is an area, not a product. Stretch a rubber band and watch half of force times extension be wrong.

A.3 Work, energy and power

The Skate Park

The track can push and cannot pull, and that one sentence is the whole topic.

A.3 Work, energy and power

Oscillations

Simple harmonic motion · Damping and resonance

Mass on a Spring

Hooke's law becomes a = -(k/m)x in one step, with the line that defines SHM drawn.

C.1 Simple harmonic motion

Simple Pendulum

The exact swing against the small-angle one, and where they part company.

C.1 Simple harmonic motion

Damping and Resonance

Sweep the driving frequency and build the resonance curve, sharpening as damping falls.

C.1 Simple harmonic motion

Waves and sound

The wave model · Standing waves · Sound · Water waves

Wave Anatomy

One particle tracked, so you can see why one graph gives a period and the other a wavelength.

C.2 The wave model

Wave Speed on a String

Work through eight masses and weigh a metre of string off the gradient.

C.2 The wave model

Standing Waves

Slide the reflection to zero and watch the pattern start travelling again.

C.4 Standing waves and resonance

Harmonics and Pipes

Switch to the closed pipe and watch the even modes be rejected.

C.4 Standing waves and resonance

Resonance Tube

Work through all eight forks and read the speed of sound off the gradient.

C.4 Standing waves and resonance

The Doppler Effect

Push the source past the speed of sound and watch the cone appear out of the wavefronts.

C.5 Doppler effect

Ripple Tank

Every length to scale, with a printed rule: make the gap one wavelength and watch a beam stop being a beam.

C.3 Wave phenomena

Light and optics

Refraction · Interference and diffraction

Refraction and Total Internal Reflection

Turn on the wavefronts to see why a ray bends at all, then send white light near the critical angle.

C.3 Wave phenomena

Young's Double Slit

A real Huygens wave goes through, and the pattern is what the screen records of it.

C.3 Wave phenomena

Single Slit

The envelope that modulates every double-slit pattern, built from the slit itself.

C.3 Wave phenomena

Diffraction Grating

Add slits and watch the maxima sharpen, with the orders where the sum says they are.

C.3 Wave phenomena

Thin Film

The colour of oil on water, worked out from the two reflections and the eye's response.

C.3 Wave phenomena

Electricity and magnetism

Circuits · Induction

Internal Resistance

Kirchhoff's laws are solved rather than the formulas quoted: load the divider and watch the reading sag.

B.5 Current and circuits

The Faraday Bench

Move the magnet by hand and the meters read how fast the flux is changing, and nothing else.

D.4 Induction

Fields

Gravitation

Gravitational Fields

Newton's law added up and integrated: find the saddle, then weigh the planet off an orbit.

D.1 Gravitational fields

Thermal physics

Gas laws

The Ideal Gas

Three hundred hard spheres, a draggable piston, and the walls asked how hard they were hit.

B.3 Gas laws

Quantum physics

Photons

The Photoelectric Effect

Photons land one at a time, and the stopping potential is found rather than quoted.

E.2 Quantum physics

Compton Scattering

The shift solved from the two conservation laws, not quoted from the formula.

E.2 Quantum physics