We all have that one friend whose opinion is seemingly different from everyone’s. Even when everyone else agrees that the sky is blue, he is willing to argue that the sky is in fact red, or yellow. And there is nothing that anyone can do to change his mind. That friend is very much like the force of friction.
It is the kind of force that comes into play for the sole purpose of opposing other forces. Turns out even forces cannot always agree with each other, any more than we human beings can.
The force of friction against the world
The force of friction has only one job: to oppose relative motion between two surfaces in contact. Three things are necessary for the force of friction to occur:
- Surfaces
- Contact
- Motion
We can even make a “friction triangle” similar to the familiar fire triangle that we are all aware of. We are going to be looking at each element and how it affects the force of friction.
Surfaces
A surface is any part of a body that is positioned in such a way that the force of friction occurs on it. So, one way of avoiding friction is removing the “surface” on which the force of friction acts – but alas! The surface is inevitably connected to the rest body and removing the “surface” means removing the body entirely. This isn’t quite an option. So, onto the next one.
Contact
In the context of the force of friction, contact means that two or more bodies are in close enough proximity that they physically touch each other. It comes as no surprise that when two or more bodies touch each other, a wide range of forces (called contact forces) may come into play. One of these forces, friction, comes into play when the bodies in contact try to move against one another.
Depending on the configuration and nature of the contact, other forces such as Spring Force, Normal force, and Tension force may also come into play.
Motion
In physics, motion is said to occur when a body changes its position over time. But as far as the force of friction is concerned, motion isn’t necessary to invoke friction. Even without motion, there is a force of friction that prevents the motion (static friction) and after the body starts moving, there is a force of friction that continues to oppose the motion (kinetic/ dynamic friction).
Combating the force of friction
Friction is kind of a menace in the engineering world and thus, engineers and designers are in a constant battle to try and reduce friction as much as possible. Most of our machines involve body parts that are in contact sliding past one another. Thus, a good amount of energy is used to overcome friction. This leads to energy losses.
One such remedy for combating this problem is by lubricating machine parts. This creates a thin film, typically of oil, between touching machine parts greatly helps to reduce friction, save energy, and tear and wear of machine parts.
But alas! The force of friction cannot be eliminated completely. It is, as Thanos once said, “Inevitable”.
