Lift & Apparent Weight Simulation

A weighing scale measures how hard it pushes up on you — the normal force — not the pull of gravity. Standing still or moving at a steady speed, that push equals your weight. In an accelerating lift the scale must also supply the force that accelerates you, so it reads N = m(g + a) with a taken positive upwards.

This lift simulation puts a person on a bathroom scale and runs a trip: speeding up, cruising and slowing down on the way up or down, or a cable that snaps. The scale, its graph and the force arrows update together, so you can see that the reading depends on the acceleration alone, and that it drops to zero in free fall — apparent weightlessness.