# Force Vector Diagram

Force is a fundamental concept in physics that describes the influence that can cause an object to change its velocity, i.e., to accelerate, meaning a change in speed or direction, unless counterbalanced by other forces . The concept of force makes the everyday notion of pushing or pulling mathematically precise. Because the magnitude and direction of a force are both important, force is a vector quantity .

A vector quantity is a quantity that has both magnitude and direction. The SI unit of force is the newton (N), and force is often represented by the symbol F . The magnitude of a force is measured in newtons, and its direction is described using a coordinate system .

Forces can be due to phenomena such as gravity, magnetism, or anything that might cause a mass to accelerate . Types of forces often encountered in classical mechanics include elastic, frictional, contact or “normal” forces, and gravitational . The rotational version of force is torque, which produces changes in the rotational speed of an object .

In an extended body, each part often applies forces on the adjacent parts; the distribution of such forces through the body is the internal mechanical stress . The internal mechanical stress is a tensor field that describes the distribution of forces and torques within a body .

In summary, force is a vector quantity that describes the influence that can cause an object to change its velocity, i.e., to accelerate, meaning a change in speed or direction, unless counterbalanced by other forces. The magnitude of a force is measured in newtons, and its direction is described using a coordinate system. Forces can be due to phenomena such as gravity, magnetism, or anything that might cause a mass to accelerate. The internal mechanical stress is a tensor field that describes the distribution of forces and torques within a body.