Further Applications of Newton's Laws

Net force affects the motion, postion and/or shape of objects (some important and commonly used forces are friction, drag and deformation).

If two systems are in contact and moving relative to one another, then the friction between them is called kinetic friction.

Static friction is a type of friction that occurs to resist motion when two objects are at rest against each other.

Combining motion on inclines with friction uses such concepts as equilibrium and contact force on an incline.

The drag force is the resistive force felt by objects moving through fluids and is proportional to the square of the object's speed.

The ratio of force to area $\frac{F}{A}$ is called stress and the ratio of change in length to length $\frac{\Delta L}{L}$ is called the strain.

An object is said to be in equilibrium when there is no external net force acting on it.

Forces can be transferred from one object to another through connections.

An object in circular motion undergoes acceleration due to centripetal force in the direction of the center of rotation.