What Is a Force?

I learn most of the concepts in physics with an intuitive manner of picturing the concept with general thought experiments. I feel that this gives a better start to understand the numerical representation of the physics behind anything. In this article and in the upcoming articles, I will share my thoughts on how to get a physical idea of the fundamental and even some complex physics terms. I will start with Force.

Force

When you think of the term force, the only things that come to your mind are the newton’s three laws of motion and the force vectors you might have seen in your schoolbooks. Have you ever tried to imagine what force could look and feel like in real life? Most of you would think that the gravity is a force that is pulling you down. Is that what you are really feeling?

Normal force

Newton’s third law states that for every action there is an equally opposite reaction. When gravity is acting upon you, there is an equally opposite force acting on you, exerted by the ground you are standing on. This is known as a normal force or reaction force. This is the actual force you feel on your body. If there is no ground beneath you, you will be falling down without any force acting on you, considering there is no air to show you the resistance effects. This is scientifically known as free-fall. Discussing the gravity is beyond the scope of this article.

Contact forces and distant forces

When forces interact with the object, they are known as forces due to contact. When forces interact without contact with the objects, like a magnet, it is called as distant forces.

Bottom line

The bottom-line is you could simply explain a force as something that pushes or pulls an object to change its state of motion relative to an inertial frame of reference. When the forces are balanced, the object being acted by the forces will be stationary or in a constant velocity. When there is an unbalanced force acting from one direction, then the body will start to accelerate. This is what is described in our textbooks in the form of vectors. This is also my cue to finish my homework. Therefore, I will stop here, and let the thought sink in.

In my next article, I will help you understand what a frame of reference means. Have a nice day all.

This post was first published on May 10, 2005.