13. the equilibrium rule states that the vector sum of all forces acting on a a) body at rest is zero. b)…

13. the equilibrium rule states that the vector sum of all forces acting on a a) body at rest is zero. b) body in uniform motion is zero. c) non - accelerating body is zero. d) all of the above
Answer
Brief Explanations:
The equilibrium rule applies to a body at rest (static equilibrium), a body in uniform motion (dynamic equilibrium), and non - accelerating bodies as they all have a net force of zero. A body at rest has zero acceleration, a body in uniform motion has zero acceleration, and a non - accelerating body has zero acceleration. According to Newton's second law $F = ma$, when $a = 0$, the net force (vector sum of all forces) $F_{net}=0$.
Answer:
D. all of the above