More Lessons: http://www.MathAndScience.com Twitter: https://twitter.com/JasonGibsonMath In this lesson, you will learn the definition of work in physics. In physics, work is defined to be the dot product of the force vector and the displacement vector. In more conventional terms, it is the produce of force times distance. If the force and distance are not in the same direction, the dot product introduces the cosine of the angle between the vectors which uses the force in the direction of motion for the calculation. Work has units of Joules, which is the same unit for potential energy and kinetic energy. Because of this, work can be used to calculate how much energy a system gains or loses in a process.