Simulations

Hang two masses from a string over a pulley — adjust each mass, gravity, the pulley's own mass, and rope/pulley friction to see which side descends, how their tensions differ, and watch the balanced case where equal masses simply hang still.

Heat an object toward a chosen target temperature and watch it glow the colour a real blackbody emits — deep red to blue-white — while its radiated power rises steeply with temperature.

Fire a charged particle into a uniform magnetic field (a closed cyclotron circle), add a uniform electric field (a bending parabola), or combine both to see the guiding center drift sideways — adjust charge sign, mass, speed, and both fields.

Send two disks toward each other with a chosen impact parameter — adjust their masses, starting speeds, and how off-center the hit is to see a head-on collision exchange velocities and a glancing one deflect both disks sideways, momentum and kinetic energy conserved exactly.

Fire a charge into a uniform magnetic field, perpendicular to its velocity — adjust the entry speed, field strength, and charge-to-mass ratio to see the radius and period of the resulting circular orbit.

Fly a sound source past a fixed observer — adjust its speed, true pitch, the speed of sound, and how close it passes to hear (and see, in the compressed and stretched wavefronts) the classic pitch glide, and watch a Mach cone form once it goes supersonic.

Hinge a second rod off a swinging pendulum's bob and release both from a large starting angle — watch a genuinely chaotic system where a fraction-of-a-degree difference in the start sends it on a completely different path.

Shine coherent light through two narrow slits and watch the exact bright/dark fringe pattern form on a screen — adjust wavelength, slit separation, slit width, and screen distance to see the fringes tighten, widen, and even lose whole orders to the single-slit diffraction envelope.

Push a damped mass on a spring with a sinusoidal driving force — sweep the driving frequency through the natural frequency and watch the transient build into a steady-state oscillation, tracing out the resonance curve as you go.

Slide a bar magnet through a coil — adjust its speed, the coil's turns, and the magnet's strength to see the induced EMF rise, peak, flip sign as the magnet passes through, and fade as it recedes.

Live interactive gas cylinder — set the amount of gas, then drag temperature and applied pressure and watch the piston respond in real time as PV=nRT holds exactly.

Watch a planet trace an exact elliptical orbit with the star at one focus, its equal-time sectors shaded to show equal-area sweeps, and a second comparison planet whose period and semi-major axis satisfy the same T^2/a^3 ratio.

Drive a series RLC circuit with an AC source — sweep the drive frequency through the resonant frequency and watch the steady-state current amplitude peak, with the peak's sharpness controlled by the circuit's resistance.

Load a sample of some isotope — adjust the isotope, purity, fuel amount, moderator, and cooling/control rods to see the chain reaction fizzle out, self-sustain, or run away, generation by generation.

Shine light of a chosen frequency onto a metal plate — adjust the frequency and the metal's work function to see whether an electron is ejected at all, and at what speed, exactly as Einstein's photon picture predicts.

Charge or discharge a capacitor through a resistor — adjust the source voltage, resistance, and capacitance to see the exponential voltage/current curves and the circuit's time constant.

Choose your launch bearing, injection speed, flight-path angle, and lead the Moon's own motion — simulate a real Earth-Moon transfer and see if you reach the Moon's sphere of influence. Reaching it refunds your run.

Release a hoop, a solid disk, and a solid sphere from rest together — each on its own ramp curve (straight incline, brachistochrone, exponential decay, circular arc, or parabola) — and see how both the SHAPE (moment of inertia) and the PATH decide who reaches the bottom first.

Fire a beam of alpha particles at a single heavy nucleus — adjust the alpha energy, target atomic number, particle count, and impact-parameter spread to watch Coulomb repulsion alone deflect each trajectory, most only slightly and a rare few sharply back the way they came.

Pluck a string fixed at both ends into a chosen harmonic — adjust its length, tension, and mass per unit length to see how fast, and in how many nodes and antinodes, it vibrates.

Place an object in front of a converging or diverging lens — watch the three principal rays trace out where the image forms, and see whether it's real or virtual, upright or inverted, magnified or reduced.