In this blog post, we will learn about the definition and types of friction, the meaning of the coefficient of friction, and the important role friction plays in our daily lives and safety.
Friction is a force that exists in almost every moment of our daily lives. We need friction when walking down the street, using a pencil, and even when buying things. We will explain in detail what friction is and what its characteristics are.
First, the definition of friction varies depending on the person, but it can be described as the force exerted horizontally between two objects in contact with each other. This is difficult to explain, but in simple terms, friction is the force that prevents objects from moving, as commonly defined in dictionaries. When teaching students about friction for the first time in textbooks, boxes are often used as examples. When you push a box and let go, it stops moving. The reason it stops is because of friction. It takes effort to push a box that is not moving because friction is a force that prevents the box from moving.
However, the reason why I did not define friction as it is defined in the dictionary at the beginning is because there are many other forces that hinder the movement of objects besides friction. When playing with a balloon, you can easily see that no matter how hard you hit it, it will stop immediately. In other words, there is a force that prevents the balloon from moving. However, this force is not friction, but air resistance. Furthermore, when you push down on a desk, you are clearly applying force downward, but the desk does not move downward. This means that there is a force preventing the desk from moving downward, and this force is called vertical resistance, not friction. Therefore, I defined friction by emphasizing the differences between resistance and vertical resistance. First, the difference from resistance is that friction is a force exerted by two objects on each other, and the two objects must be solid. Resistance is the force exerted by a liquid or gas on an object within it. Second, the difference from vertical force is that friction is applied horizontally to a surface. Vertical force is, as the name suggests, a force applied vertically to a surface.
One of the important characteristics of friction is the coefficient of friction. The coefficient of friction varies depending on the material and condition of the two objects and is divided into static friction and kinetic friction. The static friction coefficient is a measure of the friction force when an object is at rest, and the kinetic friction coefficient is a measure of the friction force when an object is in motion. Generally, the static friction coefficient is greater than the kinetic friction coefficient, so more force is required to start moving an object.
There are two types of friction force: static friction and kinetic friction. Static friction is the friction that occurs when an object is at rest, and it is equal in magnitude and opposite in direction to the external force. Kinetic friction is the friction that occurs when an object is in motion, and it is proportional to the vertical resistance, which is a measure of how tightly two surfaces are pressed together. Static friction does not result in energy loss because the point of application of the force does not move, but kinetic friction results in energy loss because the point of application of the force moves.
Friction plays an important role in many fields. For example, the friction between car tires and the road helps vehicles stop and change direction. In addition, the shoes used by athletes in sports are designed with friction in mind. This is because a lack of friction can cause slipping and injury. Therefore, friction is a very important factor directly related to safety.
Finally, I would like to point out one thing that people often misunderstand. It is the friction force that acts in cloud motion. The friction force that acts when a ball or wheel rolls on a surface is easy to mistake for kinetic friction because the object is in motion, but in reality, there is no friction between the contacting surfaces, so static friction acts. Therefore, there is no energy loss in cloud motion. This phenomenon can also be seen in the interaction between car tires and the road, where static friction increases the grip between the tires and the road, preventing the vehicle from slipping easily.
As you can see, friction plays a very important role in our daily lives and in various industries. A good understanding and utilization of friction will make our lives safer and more convenient.
