🔬

Free Lab

All available simulations in one place. No quizzes, no structure — just play.

1.1

Powers of Ten & Units

Measuring the Universe

Zoom from quarks to galaxies

N = 10ⁿ

1.2

Dimensional Analysis

Measuring the Universe

Drag-and-drop unit checker

[LHS] = [RHS]

1.3

Uncertainty & Measurement

Measuring the Universe

Virtual ruler with limited precision

x = x̄ ± δx

1.4

Vectors: Dot & Cross

Measuring the Universe

3D vector playground

|A + B|² = |A|² + |B|² + 2A·B

2.1

1D Kinematics

Motion in Space

Drag a car, see x(t), v(t), a(t) graphs

x = x₀ + v₀t + ½at²

2.2

Projectile Motion

Motion in Space

Launch projectiles at various angles

y = v₀sinθ·t − ½gt²

2.3

Circular Motion

Motion in Space

Spin a ball on a string

a = v²/r

2.4

Reference Frames

Motion in Space

Two observers, one on a moving train

v' = v + V

3.1

Newton's Three Laws

Newton’s Laws & Forces

Push objects of different masses

F = ma

3.2

Weight & Weightlessness

Newton’s Laws & Forces

Elevator scale simulator

N = m(g + a)

3.3

Free Fall & Orbit

Newton’s Laws & Forces

ISS orbit — objects float but gravity is there

v_orbit = √(gR)

3.4

Friction

Newton’s Laws & Forces

Push blocks on surfaces, adjust μ

f ≤ μN

3.5

Inclined Planes

Newton’s Laws & Forces

Adjustable ramp with blocks

a = g(sinθ − μcosθ)

4.1

Hooke's Law & Springs

Energy & Work

Stretch springs, see F vs x

F = −kx

4.2

Simple Harmonic Motion

Energy & Work

Mass on spring + pendulum side by side

T = 2π√(m/k)

4.3

Work & Kinetic Energy

Energy & Work

Push a cart, see work integral

W = ΔKE = ½mv²

4.4

Potential Energy & Conservation

Energy & Work

Roller coaster designer

½mv² + mgh = const

4.5

Universal Gravitation

Energy & Work

Place masses, see gravitational field

F = GMm/r²

4.6

Orbits & Escape Velocity

Energy & Work

Launch a rocket — crash, orbit, or escape

v_esc = √(2GM/R)

4.7

Terminal Velocity

Energy & Work

Drop shapes through fluid

v_t = √(2mg/ρCₐA)

5.1

Momentum & Impulse

Momentum & Collisions

Ball vs wall vs catcher

J = FΔt = Δp

5.2

Conservation of Momentum

Momentum & Collisions

Billiards — 2D elastic collisions

m₁v₁ + m₂v₂ = m₁v₁' + m₂v₂'

5.3

Elastic vs Inelastic

Momentum & Collisions

Crash carts, compare energy loss

KE_lost = ½μv_rel²

5.4

Center of Mass

Momentum & Collisions

Place masses, find COM trajectory

x_cm = Σmᵢxᵢ / M

5.5

Rocket Equation

Momentum & Collisions

Build a rocket, adjust fuel

Δv = vₑ ln(m₀/mf)

6.1

Moment of Inertia

Rotation & Angular Momentum

Spin different shapes, compare I

I = cmR²

6.2

Torque

Rotation & Angular Momentum

Wrench simulator

τ = r × F

6.3

Angular Momentum

Rotation & Angular Momentum

Ice skater — arms in/out

L = Iω = const

6.4

Physical Pendulums

Rotation & Angular Momentum

Hang shapes from different pivots

T = 2π√(I/mgd)

6.5

Kepler's Laws

Rotation & Angular Momentum

Solar system builder

T² = (4π²/GM) a³

6.6

Rolling Motion

Rotation & Angular Momentum

Race: cylinder vs sphere down ramp

a = g sinθ / (1 + I/mR²)

6.7

Gyroscopes & Precession

Rotation & Angular Momentum

3D gyroscope

Ω = τ/L = mgd/Iω

7.1

Static Equilibrium

Statics & Elasticity

Balance beams

ΣF = 0 and Στ = 0

7.2

Stability & Tipping

Statics & Elasticity

Stack blocks, lean a tower

θ_tip = arctan(w / 2h)

7.3

Tightrope Walker

Statics & Elasticity

Walk a figure across a rope

α = τ / I

7.4

Elasticity & Young's Modulus

Statics & Elasticity

Stretch materials, see stress-strain

σ = E · ε (F/A = E · ΔL/L)

8.1

Hydrostatic Pressure & Pascal

Fluids

Hydraulic press

P = P₀ + ρgh

8.2

Atmospheric Pressure

Fluids

Barometer at different altitudes

P_atm ≈ 101,325 Pa

8.3

Archimedes & Buoyancy

Fluids

Sink or float?

F_b = ρ_fluid · V_displaced · g

8.4

Bernoulli's Equation

Fluids

Funnel demo + pipe flow lab

P + ½ρv² + ρgh = const

9.1

Thermal Expansion

Heat & Kinetic Theory

Ball and ring demo

ΔL = αLΔT

9.2

Kinetic Gas Theory

Heat & Kinetic Theory

Box of bouncing molecules

½mv² = (3/2)kT

9.3

Ideal Gas Law

Heat & Kinetic Theory

Piston chamber

PV = nRT

9.4

Phase Transitions

Heat & Kinetic Theory

Heat water ice→steam

Q = mL

10.1

Breakdown of Classical Mechanics

The Quantum Frontier

Double-slit, one particle at a time

ψ = ψ₁ + ψ₂

10.2

Wave-Particle Duality

The Quantum Frontier

Toggle wave vs particle view

λ = h/p

10.3

Uncertainty Principle

The Quantum Frontier

Measure position vs momentum tradeoff

Δx·Δp ≥ ħ/2

11.1

Coulomb's Law

Electric Charges & Fields

Place charges, see forces

F = kq₁q₂ / r²

11.2

Polarization

Electric Charges & Fields

Charged rod near neutral objects

Q₁ + Q₂ = Q₁′ + Q₂′

11.3

Electric Field Lines

Electric Charges & Fields

Place charges, see field lines

E = F / q = kQ / r²

11.4

Gauss's Law

Electric Charges & Fields

Draw Gaussian surfaces

Φ = Q_enc / ε₀

12.1

Electrostatic Potential

Electric Potential & Energy

Topographic voltage map

V = kq / r

12.2

E = −∇V

Electric Potential & Energy

Draw potential, see E-field emerge

E = -∇V

12.3

Faraday Cage

Electric Potential & Energy

Charge inside/outside a cage

Eᵢₙₛᵢ₂ₑ = 0

12.4

Lightning

Electric Potential & Energy

Build charge → watch lightning strike

E > 3 × 10⁶ V/m

13.1

Capacitance

Capacitors & Dielectrics

Adjust plates, see C change

C = ε₀A / d

13.2

Electric Field Energy

Capacitors & Dielectrics

Visualize stored energy

U = ½C V² = ½Q V = Q² / 2C

13.3

Dielectrics

Capacitors & Dielectrics

Insert materials between plates

C = κε₀A / d

13.4

Van de Graaff Generator

Capacitors & Dielectrics

Charge it up, see sparks

E = σ / ε₀

14.1

Ohm's Law

Circuits

Wire with electron flow

V = IR

14.2

Resistivity

Circuits

Compare copper, rubber, silicon

R = ρL / A

14.3

Batteries & EMF

Circuits

Build circuits with bulbs

V = ε − Ir

14.4

Kirchhoff's Rules

Circuits

Complex circuit builder

ΣI_in = ΣI_out | ΣV_loop = 0

15.1

Lorentz Force

Magnetic Fields & Forces

Shoot charges through B-field

F = qv × B

15.2

Cyclotron

Magnetic Fields & Forces

Mass spectrometer — sort isotopes

r = mv / (qB)

15.3

Biot-Savart Law

Magnetic Fields & Forces

Draw wire, see B-field

B = μ₀I / (2πr)

15.4

Ampère's Law & Solenoids

Magnetic Fields & Forces

Wrap coils, see field

B = μ₀nI

16.1

Faraday's Law

Electromagnetic Induction

Move magnet through coil

ε = -N dΦ/dt

16.2

Lenz's Law

Electromagnetic Induction

Drop magnet through copper tube

ε = -dΦ/dt

16.3

Dynamos & Generators

Electromagnetic Induction

Spin generator, see AC output

ε = NBAω sin(ωt)

16.4

Eddy Currents

Electromagnetic Induction

Pendulum between magnets

F ∝ σvB²

16.5

Magnetic Levitation

Electromagnetic Induction

Levitate magnet — Meissner effect

B = 0 (inside superconductor)

16.6

Aurora Borealis

Electromagnetic Induction

Solar particles → Earth’s field → aurora

F = qv × B

17.1

Inductance & RL Circuits

Inductors, Magnetism & Maxwell

RL circuit — current ramp

I(t) = (V/R)(1 − e^(−t/τ))

17.2

Magnetic Field Energy

Inductors, Magnetism & Maxwell

Energy in inductor’s field

U = ½LI² = B²V/(2μ₀)

17.3

Dia/Para/Ferromagnetism

Inductors, Magnetism & Maxwell

Materials in B-field

M = χₘH

17.4

Hysteresis

Inductors, Magnetism & Maxwell

Trace hysteresis loop

B = μ₀(H + M)

17.5

Maxwell's Equations

Inductors, Magnetism & Maxwell

All four equations visualized

∇×B = μ₀J + μ₀ε₀(∂E/∂t)

18.1

Transformers

AC Circuits & Resonance

Adjust turns ratio

V₂/V₁ = N₂/N₁ = I₁/I₂

18.2

RC Circuits

AC Circuits & Resonance

Charge/discharge curve

V(t) = V₀(1 − e^(−t/RC))

18.3

LRC Resonance

AC Circuits & Resonance

Sweep frequency, find peak

ω₀ = 1/√(LC)

18.4

Impedance & Phasors

AC Circuits & Resonance

Rotating phasor diagram

Z = √(R² + (X_L − X_C)²)

19.1

Traveling EM Waves

EM Waves & Optics

E and B fields propagating at c

c = λf = 1/√(ε₀μ₀)

19.2

Speed of Light

EM Waves & Optics

Historical methods to measure c

c = 4D × N × f

19.3

Radiation Pressure

EM Waves & Optics

Solar sail spacecraft

P = 2I/c (reflection)

19.4

Snell's Law & Refraction

EM Waves & Optics

Light into glass — adjust angle

n₁ sinθ₁ = n₂ sinθ₂

19.5

Polarization

EM Waves & Optics

Stack polarizers, rotate

I = I₀ cos²θ

19.6

Rainbows

EM Waves & Optics

Sunlight entering a raindrop

θ = 4r - 2i (Descartes)

19.7

Double-Slit Interference

EM Waves & Optics

Adjust slits, see pattern

d sinθ = mλ

19.8

Diffraction & Gratings

EM Waves & Optics

Single slit, gratings, CD

a sinθ = mλ (dark fringes)

19.9

Doppler Effect

EM Waves & Optics

Move source — see red/blueshift

f′ = f₀ × (v + v_obs)/(v - v_src)

20.1

SHO & Phasors

Oscillations Revisited

Phasor + real oscillation

x(t) = A cos(ωt + φ)

20.2

Beats

Oscillations Revisited

Two tuning forks — hear beats

f_beat = |f₁ − f₂|

20.3

Damped Oscillations

Oscillations Revisited

Adjust damping — see 3 regimes

x(t) = A·e^(−γt)·cos(ω′t + φ)

20.4

Driven Resonance

Oscillations Revisited

Drive spring-mass, sweep freq

A(ω) = F₀/m / √[(ω₀² − ω²)² + (2γω)²]

20.5

Power at Resonance

Oscillations Revisited

Energy peak — wine glass physics

Q = ω₀ / Δω = ω₀ / (2γ)

20.6

Transient Phenomena

Oscillations Revisited

Turn driver on/off, see ring up/down

x(t) = x_ss(t) + A₀·e^(−γt)·cos(ω₀t + φ₀)

21.1

Two Coupled Oscillators

Coupled Oscillators & Normal Modes

Two pendulums + spring

ω₁ = √(g/L), ω₂ = √(g/L + 2k/m)

21.2

Normal Modes

Coupled Oscillators & Normal Modes

Symmetric + antisymmetric modes

ω_sym = √(g/L), ω_anti = √(g/L + 2k/m)

21.3

Many Coupled Oscillators

Coupled Oscillators & Normal Modes

Chain of masses — standing waves

ω_n = 2√(k/m) · sin(nπ / 2(N+1))

21.4

Discrete → Continuous

Coupled Oscillators & Normal Modes

N from 2 → 100, see waves emerge

v = √(T/μ) = a√(k/m)

21.5

The Wave Equation

Coupled Oscillators & Normal Modes

Animated derivation

∂²y/∂t² = v² ∂²y/∂x², v = √(T/μ)

22.1

Traveling Waves

Waves on Strings & Sound

Pluck string, see pulse travel

v = √(T/μ)

22.2

Standing Waves & Harmonics

Waves on Strings & Sound

Guitar string harmonics

fₙ = n · v/(2L) n = 1, 2, 3...

22.3

Energy in Waves

Waves on Strings & Sound

Energy density moving with wave

P = ½μA²ω²v

22.4

Sound Cavities

Waves on Strings & Sound

Open/closed tube resonances

fₙ = nv/(2L) (open) fₙ = nv/(4L) (closed, odd n)

22.5

Musical Instruments

Waves on Strings & Sound

Virtual guitar, flute, drum

f(t) = Σ Aₙ sin(nωt + φₙ)

22.6

Fourier Analysis

Waves on Strings & Sound

Build waveforms from sine waves

f(t) = a₀/2 + Σ[aₙcos(nωt) + bₙsin(nωt)]

23.1

Dispersion & Group Velocity

EM Waves (Advanced)

Wave packet spreading

vₑ = dω/dk = vₚ + k(dvₚ/dk)

23.2

EM Wave Solutions

EM Waves (Advanced)

3D E, B, Poynting vector

S = (1/μ₀)(E × B)

23.3

Rayleigh Scattering

EM Waves (Advanced)

Why the sky is blue

I ∝ (1/λ⁴) · (1 + cos²θ)

23.4

Radiation & Reflection

EM Waves (Advanced)

Light bouncing off mirrors

P = 2I/c (perfect reflection)

23.5

Waveguides

EM Waves (Advanced)

EM waves in a box

f_c = c/(2a) (TE₁₀ mode)

23.6

Brewster's Angle

EM Waves (Advanced)

Reflection at Brewster angle

tan θ_B = n₂/n₁

24.1