Virtual Physics LabElectricity, Fields, Waves & Energy

Physics Interactive Lab

Experiment with circuits, fields, waves, and energy through interactive physics simulations.

All 5 Labs Hub →
Source f₀: 440 HzMedium Speed v: 343 m/s
-100m-50m0m50m100mvs = +60 m/sSource (Speaker)-80mObserver (Detector)80m
t = 0.00 s/ 4.0s
Sim Time: 0.00s
Emitted Pitch (f₀)440 Hz
Observed Pitch (f')533.3 Hz
Frequency Shift (Δf)+93.3 Hz(+21.2%)
Wavelength Ahead (λ)0.64 mBehind: 0.92 m
Observed Frequency f' over Time[Hz]

Source Natural Frequency (f₀)440 Hz
Medium Wave Speed (v)343 m/s
Default 343 m/s for sound in standard 20°C air
Source Velocity (vs)+60 m/s (Toward Observer)
Observer Velocity (vo)0 m/s (At Rest)

Auditory Pitch Demo

Auditory tone synthesizer plays observed frequency pitch. Never autoplays.

Governing Doppler Equation
f' = f₀ · (v ± v₀) / (v ∓ vₛ)
f' = 440 Hz · (343 + 0) / (343 - 60)
Calculated f' = 533.3 Hz

When the source moves toward the observer, each successive wave crest is launched closer to the previous one, compressing the wavelength in space and raising the detected pitch.

Physics Conceptual Challenge

Question 1 of 4

When a sound source moves toward a stationary observer, what causes the observed frequency to increase?

Virtual Experiment Data Log

Record live trials, compare outcomes, and export CSV data for lab reports.

No measurements logged yet. Click “Record Measurement” to save the current parameters and live calculated values.

Guided Scientific Investigations

Experiment 1: Verify Ohm’s Law

Keep resistance fixed at 6 Ω, vary voltage from 2V to 24V, and plot the linear V–I relationship.

Experiment 2: Inverse-Square Field Law

Place one positive charge and measure electric field magnitude at distances r = 0.5m, 1.0m, 1.5m, and 2.0m.

Experiment 3: Current & Magnetic Field

Select straight wire, reverse current from +10A to -10A, and verify the Right-Hand Rule field reversal.

Experiment 4: Doppler Frequency Shift

Keep observer stationary and sweep source velocity vs from -150 m/s to +150 m/s to measure Δf.

Experiment 5: Conservation of Mechanical Energy

Release cart from 20m, pause at waypoints A, B, C, D and compare PE + KE = constant in frictionless mode.

Unified Physical World

Cross-Lab Physical Connections

Physics is not a collection of isolated equations. Observe how electrical potential difference creates electric field gradients, charges in motion constitute current, moving charges generate magnetic fields, vibrations create wave pulses, and mechanical forces obey strict energy conservation.

SI Reference Units & Definitions

Voltage (V)Volt [J/C] — Electric potential difference driving charge flow.
Current (A)Ampere [C/s] — Rate of electric charge transport through a cross section.
Electric Field (E)N/C or V/m — Electrostatic force per unit positive test charge.
Magnetic Field (B)Tesla [T] or μT — Magnetic flux density exerting Lorentz force on moving charges.
Frequency (f)Hertz [1/s] — Number of wave cycles passing an observer per second.
Wavelength (λ)Meter [m] — Spatial distance between consecutive wave crests.
Potential Energy (PE)Joule [J = kg·m²/s²] — Gravitational energy stored in cart position: mgh.
Kinetic Energy (KE)Joule [J] — Energy of motion possessed by mass moving with speed v: ½mv².