A calibrated trap produces a restoring force with checked magnitude. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.
highlighted = computed this step
Trap stiffness turns displacement into force
Use stiffness 2 newtons per metre with displacement 3 metres.
2⋅3
The restoring force points back
The force magnitude is 6 newtons, and the arrow points back toward the trap center.