Often, more than one force can act upon an object at a time, and the forces can push or pull in any direction. What happens to the object when forces act upon it depends on the following two things:

1. The strength of the forces
2. The direction of the forces

When more than one force acts on an object, the forces combine to form a net force. The combination of all the forces acting on an object is the net force.

If two forces of equal strength act on an object in opposite directions, the forces will cancel, resulting in a net force of zero and no movement. Two or more opposite forces are balanced forces if their effects cancel each other and they do not cause a change in an object's motion.

Click on "Check your Answer" to find the image showing balanced forces.

	Interactive popup. Assistance may be required. Check your Answer Incorrect. This picture does not show balanced forces. In order for a force to be balanced, they must be equal and in the opposite direction. These forces are equal, but are not opposite. The two forces are working together.
	Interactive popup. Assistance may be required. Check your Answer Incorrect. This picture does not show balanced forces. In order for a force to be balanced, they must be equal and in the opposite direction. These forces are opposite, but they are not equal.
	Interactive popup. Assistance may be required. Check your Answer Correct. This picture shows balanced forces. In order for a force to be balanced, they must be equal and in the opposite direction.

If the effects of the forces do not cancel each other, or if one force is stronger than the other, the forces are unbalanced forces. Unbalanced forces cause a change in motion, speed, and/or direction.

When two forces act in the same direction on an object, the net force is equal to the sum of the two forces. In the example below, the net force would be 900 Newtons (450 + 450 = 900), and the object would move to the right.

When two unequal forces act in opposite directions on an object, the net force is the difference of the two forces. In the example below, the net force would be 50 Newtons (500 - 450 = 50), and the object would move to the left because the force pulling to the left is greater.

Find the Net Force

In the problems below, find the net force, and then select what direction the object will move. The dot represents the object the forces are acting upon and the arrows show the direction the force is moving.