The net force on an object is calculated by combining the different forces being exerted on the object if the forces are on the same axis. When more than one axis is involved, the net force for each axis must be found. The Pythagorean Theorem is then used to find the net force.
Forces are classified as positive or negative. Force exerted to move an object to the right are positive forces. Those moving an object to the left are negative forces. If two equal forces from opposite sides are applied to an object, they negate each other, and the net force is zero. When there is only one force acting on an object, that force becomes the net force. Two forces working in the same direction are added together for the net force.
The rate of acceleration of an object is directly proportionate to its net force. The direction an object moves or accelerates is determined by the direction of the net force. Gravity and friction are forces that must be considered when determining net force. Once found, the net force indicates the direction and speed at which an object moves. Changing one of the forces or increasing friction or gravity change the speed and direction of an object.