Question

Why is spring force negative?

Answer 1

Spring force is negative because:

According to Hooke's Law,

:$F=-kx$ Where, $F$ = Force exerted by spring, $k$ = spring constant, $x$ = displacement (extension/compression) in spring

1. The force exerted by spring is always in the opposite direction of the displacement. When spring is pulled downward it will exert a force in the upward direction.
2. Spring always opposes displacement.
3. Spring force is called restoring force.

Hence spring force is negative.