Gyroscopic Precession Lab
Spin a wheel fast, hang a weight off its axle, and watch the whole axle slowly sweep around instead of falling - real torque-induced precession.
Spin the wheel fast, hang a weight off one end of its axle, and watch the whole axle slowly sweep around (precess) instead of falling — the faster the spin, the slower the precession.
About the Gyroscopic Precession Lab
Free gyroscopic precession lab. Spin a wheel fast, hang a weight off its axle, and watch the whole axle slowly sweep around instead of falling - real torque-induced precession. Drag, change the sliders and see the result live. No sign-up, works on phone and computer. Built for physics, the gyroscopic precession lab runs instantly in your browser: change a setting or drag an object and the result updates at once, so you learn by trying things out rather than only reading about them.
Spin a wheel fast, hang a weight off its axle, and watch the whole axle slowly sweep around instead of falling - real torque-induced precession. Use it to explore physics ideas at your own pace, then check what you found against the key ideas further down this page.
How to use the Gyroscopic Precession Lab
- Use the controls to change Spin rate ω_spin, Hanging weight mass m, Lever arm r (weight to pivot), Wheel moment of inertia I. The simulation reacts instantly.
- Press "Reset to defaults", "Lab Report" to start, reset or change what is happening.
- Where you see a glowing handle, object, weight or atom, drag it with your mouse or finger. Everything responds in real time.
- Watch the readouts and graphs update as you experiment, and compare what you see with the key ideas below.
Things to try
- Double the spin rate and watch the precession rate halve.
- Increase the hanging weight and watch precession speed up.
- Predict the precession period, then check it against the readout.
- Try a very light wheel and see how fast it precesses.
Key ideas you can learn
- A spinning gyroscope resists tipping over; instead, an applied torque makes its spin axis sweep sideways (precess) rather than falling in the direction of the torque.
- Precession rate is Ω = τ / (I ω_spin): faster spin or a larger moment of inertia means slower, more stable precession for the same torque.
- The torque causing precession here comes from gravity acting on an off-center hanging weight, τ = mgr.
- This same physics keeps a spinning bicycle wheel, a top, and Earth's own slow 26,000-year axial precession stable against toppling.
Show my work
Challenges
Challenge 1 - predict the precession period
Using the sliders' current values, compute the precession period T = 2π / Ω where Ω = τ / (I·ω_spin) and τ = m g r (g = 9.8 m/s²). Enter your predicted period in seconds.
Challenge 2 - double the spin rate
Note the current precession rate Ω. If you were to exactly double the spin rate ω_spin (keeping everything else fixed), by what factor would Ω change? Enter the factor (e.g. 2 or 0.5).
Where this is used in the real world
Gyroscopic precession is used in gyrocompasses for ships and aircraft, in bicycle and motorcycle stability, and it explains the slow 26,000-year wobble of Earth's own rotation axis.
Who is this simulation for?
Physics students in middle school, high school and first-year university, teachers who want a quick demonstration for the projector, and anyone revising for exams. It works well for flipped classrooms because students can explore before the lesson.
For teachers: project it on the board, let students predict what will happen, then run it together. For students: change one thing at a time and write down what changes.
Frequently asked questions
Why does a fast-spinning gyroscope precess sideways instead of falling over?
The torque changes the direction of the angular momentum vector rather than its magnitude; since angular momentum is already large and aligned with the spin axis, the torque can only rotate that axis sideways, which is precession.
Why does precession slow down when you spin the wheel faster?
Precession rate Ω = τ/(Iω_spin) is inversely proportional to the spin rate, so a faster-spinning wheel has more angular momentum to redirect for the same torque, making it precess more slowly.
Is the Gyroscopic Precession Lab free to use?
Yes. It is completely free, with no signup, no download and no ads inside the simulation. It runs in your web browser.
Does the Gyroscopic Precession Lab work on a phone or tablet?
Yes. It uses touch as well as the mouse, so you can drag objects with your finger. A larger screen makes the controls easier to see.