Explore the Center of Mass & Balance
Drag weights on a beam and place the support so it balances at the centre of mass. Free, no signup, runs in your browser.
- Free to use
- No signup
- Nothing to install
- Runs in your browser
Illustration. Open the tool for the real thing.
See it in action
The Center of Mass & Balance with sample data entered and the result showing.
What is the Center of Mass & Balance?
Drag weights on a beam and place the support so it balances at the centre of mass. It runs in your browser, so a change to a setting or a drag on an object shows up at once.
Cranes, ships, cars (low centre of mass for stability), gymnasts and high-jump athletes all use centre-of-mass thinking.
3 steps to your result
Open the tool and follow along. Nothing to install.
What you get
The centre of mass is the mass-weighted average position.
A beam balances when the support is under the centre of mass.
Torque = weight × distance from the pivot.
Balance the beam by moving only the support.
Balance it by moving only a weight.
Make one weight 10 kg and see how far the centre of mass moves.
Used for
Pick one to see how it fits.
Physics learners
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.
Try it freeTeachers
For teachers: project the Center of Mass & Balance on the board, let students predict the result, then run it together and test this: Balance it by moving only a weight. For students: change one thing at a time and write down what changes.
Try it freeHow it compares
A plain look at this tool next to the usual alternative.
| This simulation | Textbook diagram | |
|---|---|---|
| Interactive | Drag, tap and change settings | Fixed picture |
| Install | Nothing to install | Not needed |
| Cost | Free to use | Depends on the book |
Questions people ask
How do you find the centre of mass?
Sum of (mass × position) divided by total mass.
Why does a beam tip?
The torques on the two sides of the support are unequal.
Is the Center of Mass & Balance free to use?
Yes. The Center of Mass & Balance is free, needs no signup or download and runs in your web browser. It is part of the Physics group of AZRS simulations.
Does the Center of Mass & Balance work on a phone or tablet?
Yes. The Center of Mass & Balance takes touch input as well as mouse input, so you can use its 3 adjustable settings with a finger. A larger screen makes the controls and graphs easier to read.
How do I use the Center of Mass & Balance?
1. In the Center of Mass & Balance, use the controls to change Red weight, Blue weight, Green weight. The simulation reacts instantly. 2. In the Center of Mass & Balance, press "Balance it for me", "Reset" to start, reset or change what is happening. 3. Start with this experiment: Balance the beam by moving only the support. Drag any glowing handle, object or slider with your mouse or finger and the Center of Mass & Balance responds in real time. 4. Change one setting at a time and watch which readout moves, then compare it with this idea: The centre of mass is the mass-weighted average position.
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Try the Center of Mass & Balance now
Drag weights on a beam and place the support so it balances at the centre of mass. Free to use.
Try it free