What this mode does
Apply multiple forces to a central mass and watch the resultant force (green) update live. Useful for equilibrium problems, concurrent forces, and the parallelogram law.
Creating forces
Drag outwards from the mass to add a force. The drag direction sets the force's line of action; the drag length sets its magnitude.
Editing forces
Drag a force's tip to change its magnitude and direction.
Drag a force's body to reposition it — useful for arranging forces head-to-tail away from the mass.
Use the × button next to any force in the list to remove it.
Parallelogram
Tick Show parallelogram, then tap any two forces to select them. The parallelogram of those two forces is drawn, with its diagonal showing their combined effect.
Tap a selected force again to deselect it.
Equilibrium indicator
When the resultant is effectively zero, a pulsing BALANCED label appears at the mass. Useful for showing students when forces are in equilibrium.