Contact forces and action-at-a-distance forces

[Cheman]

Contact forces and action-at-a-distance forces...

Are all contact forces the result of action-at-a-distance forces? After all, surely it all boils down to electrostatic repulsions, etc?

Thanks in advance.

 

[ramollari]

Yes, you are right. There's no actual meaning of 'contact' when we talk about forces. All of them can be seen as interactions in distance, that can be elecromagnetic, gravitational, weak, and strong.
However there are now some modern theories that explain forces at distance as exchange of particles.

 

[sir-pinski]

Contact forces and action-at-a-distance forces are two types of forces that are commonly encountered in physics. Contact forces are forces that result from direct physical contact between two objects, while action-at-a-distance forces are forces that act between two objects without any physical contact. Both types of forces play a significant role in our understanding of the physical world, but they are fundamentally different in nature.

Contact forces are the result of physical interactions between objects. For example, when you push a book across a table, the force you apply to the book is a contact force. This force is transmitted through direct contact between your hand and the book, and it causes the book to move. Other examples of contact forces include friction, normal force, tension, and air resistance. These forces are all the result of physical interactions between objects, and they are often easier to visualize and understand.

On the other hand, action-at-a-distance forces do not require physical contact between objects. Instead, they act over a distance and are often described as "invisible" forces. The most common example of an action-at-a-distance force is gravity, which acts between two objects without any physical contact. Other examples include electric and magnetic forces, which also act over a distance.

Now, to answer the question of whether all contact forces are the result of action-at-a-distance forces – the answer is no. While it is true that all contact forces are ultimately the result of electrostatic repulsions and other fundamental forces, they are still considered contact forces because they require direct physical contact between objects. Action-at-a-distance forces, on the other hand, do not require physical contact and act over a distance.

In summary, contact forces and action-at-a-distance forces are two types of forces that play different roles in physics. Contact forces result from physical interactions between objects, while action-at-a-distance forces act over a distance without any physical contact. While all forces can be traced back to fundamental interactions, it is important to distinguish between these two types of forces in order to better understand the physical world.