Net force is the sum of all forces acting on an object. The net force can be calculated using Newton's second law, which states that F = ma, where: F is the net force. m is the mass of the object.
If accelerating it has a net ( unbalanced) force acting on it .
with zero net forces it will either remain at rest or continue moving (but not accelerate)
c, 1a hope this
no simpler subs form complex ones. synthesise = make