What is a Force?
- A force is a physical quantity that describes the interaction between bodies.
- When bodies interact, forces are experienced by the bodies.
- When bodies stop interacting, the forces stop.
- A force can either change the motion of an object by stopping its movement or by setting it in motion.
- It is said that a force is applied to, acts on, or is exerted on or by a body.
- As forces occur when bodies interact, it must involve at least two different objects.
- In physics however this can be simplified, showing the forces acting only on the body we are interested in.
- This can be drawn as a free-body diagram.
- Forces are vectors and thus are drawn as arrows.
- The image below shows a free-body diagram with 3 forces acting upon the body.
Adding Forces
- Forces can be added together like any other vectors of the same quantity.
- The sum of multiple forces is called the resultant force.
- The diagram below shows the forces acting on the object with the equation to find the resultant force on the right.
