Common Forces in Mechanics

An object usually experiences four primary forces. First is the gravitational force (or weight) pulling it downward. Surfaces exert normal force, while frictional force works against motion. Then the applied or tension force starts any movement. These forces can either balance each other out or be unbalanced. 

In Class 11 Physics, we typically talk about two main categories of forces. One is contact forces, and the second is non-contact forces. Contact forces are friction, tension, normal force, and spring force. On the other hand, non-contact forces consist of gravitational, electrostatic, and magnetic forces. These types of forces help us in understanding Newton's laws of motion, free-body diagrams (FBDs), and the concept of equilibrium.