PhysicsUKINTERACTIVE LAB
FORCES · BALANCE · EQUILIBRIUM

Moments Lab.

BUILD

A little weight. A little distance. Find the balance.

Drag to move an attachment.
YOUR BALANCING BEAMMake a change. See what happens.

Use Tab on the canvas to select parts. In Build, use arrow keys to adjust a selected attachment. Move drags attachments and pivots, even after Run. Pull applies a force during motion. Ruler endpoints snap to apparatus. Focus the A or B ruler button and use arrows for keyboard measurement.

100%
Drag a weight or the green pivot to edit your build.
A LITTLE HELP GETTING STARTED

Build something in balance.

  1. Arrange your apparatus. In Build, drag a part onto a beam. Click a part instead if you prefer, then click its destination. A new beam in empty space gets its own support.
  2. Make it yours. Drag weights, pivots and attachment rings. Open Properties for exact numbers, string lengths and parent attachments. Moving a branch carries everything below it. Add as many Anchor parts as you need, including during Run. Each adds a separate fixed support and string, keeping the pivot. Move the anchor or its beam attachment; set extra slack in Properties. To suspend a beam only from these anchors, select its beam and choose Remove pivot in Build.
  3. Set it moving. Press Run. Move slides weights and pivots, holding motion until you release. Choose Pull to swing the apparatus with a pulling force. Pause freezes motion; Build returns to your designed arrangement.
  4. Reveal the physics. Select a beam and turn on Forces, Moment arms or Moments. Use Ruler to measure between two draggable points; choose m or cm. It works during motion and while paused. Ruler points snap to pivots, beam ends and attachments; hold Alt for a free point. Focus the A or B button and use arrows for precise keyboard measurements. Every beam must balance, including the ones underneath.

Keyboard: Tab through parts on the canvas, arrows to move a selected attachment in Build (Shift for smaller steps), Enter for Properties, Escape to cancel placement, Delete to remove a part. Ctrl+Z / Ctrl+Y undo and redo. Space runs or pauses.

View: use +/− to zoom. Turn on Pan, or hold Space and drag the background. On touch screens, pinch to zoom and use Pan to move the view.

Progress and constructions stay in this tab only. Resetting a mode is undoable; reloading starts fresh.