Before we get into how to calculate net force, let us define force. Forces are vector quantities, which means that they have both magnitude and direction.

We can simply define the net force as the sum of all the forces acting on an object. The net force acting on an object makes the object change either its speed or direction of motion or both.

Newtons first law states that if a body is at rest or moving at a constant speed in a straight line, it will remain at rest or keep moving in a straight line at constant speed unless it is acted upon by a force. This means that understanding the net force acting on an object will help in predicting the object’s motion.

Net force is measured in Newtons.

### Formula to Calculate Net Force.

**Example 1:**

In a tug of war, one man pulls with a force of 100 N on one side, and the other man pulls with 90 N on the other side. Compute the net force.

Therefore, the net force is 10 N.

**Example 2:**

In a tug of war, one person pulls with a force of 60N on a side, and another pulls with 80N on the other side. Determine the net force.

Given:

**Force F1= 60N**

**Force F2 = -80N**

Therefore;

**F _{net} = F_{1 }+ F_{2}**

**= 60 + (-90)**

**= 60 – 90**

Hence, the net force is -10N.