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Net force


In physics, net force is the overall force acting on an object. In order to calculate the net force, the body is isolated and interactions with the environment or other constraints are represented as forces and torques in a free-body diagram.

The net force does not have the same effect on the movement of the object as the original system forces, unless the point of application of the net force and an associated torque are determined so that they form the resultant force and torque. It is always possible to determine the torque associated with a point of application of a net force so that it maintains the movement of the object under the original system of forces.

With its associated torque, the net force becomes the resultant force and has the same effect on the rotational motion of the object as all actual forces taken together. It is possible for a system of forces to define a torque-free resultant force. In this case, the net force when applied at the proper line of action has the same effect on the body as all of the forces at their points of application. It is not always possible to find a torque-free resultant force.

The sum of forces acting on a particle is called the total force or the net force. The net force is a single force that replaces the effect of the original forces on the particle's motion. It gives the particle the same acceleration as all those actual forces together as described by the Newton's second law of motion.

Force is a vector quantity, which means that it has a magnitude and a direction, and it is usually denoted using boldface such as F or by using an arrow over the symbol, such as .


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