Work

The definition of work is

Where is a small change in the displacement vector along path . It can be interpreted as the accumulated effect of a force along a path. Here we use the Dot Product.

Another interpretation is that work is a measure of how much energy is transferred in or out of a system.

The unit for work is the newton-meter () or the Joule . When dealing with subatomic particles we use the electron-volt where .

For work to happen, there must be a in the direction or in the direction. When the force is opposite the direction, there is negative work.

For Rotational Motion, for a rotation from to , work is:

Work Done on a System By External Forces Frictional Work