Your force is in the opposite direction as the movement. That is to say, the net force is the sum of all the forces, taking into account the fact that a force is a vector and two forces of equal magnitude and opposite direction will cancel each other out. The net force is the vector sum of all forces acting (pushing or pulling) on an object.

In this case, work is negative as the force applied to the goalie net is in the opposite direction of the net… Is this a thing that can happen and if so, how? Notice that the net force is aimed to the left; so, it is a negative force. Example: a box has two forces acting in opposite directions of each other, one force to the left at 12N and one force to the right at 4N. Basically, when you calculate the net force you add up the separate forces, as in: F 1 + F 2 = (-20 N) + (18 N) = -2 N = F net . In each of the above situations, there is an unbalanced force. The net force is the vector sum of all the forces that act upon an object.

Once found, the net force can be set equal to the product of mass and acceleration via Newton's second law.

Negative net force?
Two forces can cancel each other. This is shown in the following diagram. It is commonly said that in each situation there is a net force acting upon the object. When determining the net force, it is useful to draw a free-body diagram showing all of the forces. This is the opposite situation from the one above: the moving goalie net has kinetic energy, but loses kinetic energy as you slow it down.