Force
In physics, a force is any interaction that, when unopposed, will change the motion of an object. A force can cause an object with mass to change its velocity (which includes to begin moving from a state of rest), i.e., to accelerate. Force can also be described intuitively as a push or a pull. A force has both magnitude and direction, making it a vector quantity. It is measured in the SI unit of newtons and represented by the symbol F.
Joule-second
The joule-second also appears as the unit of measure in classical mechanics for the angular momentum of a rotating object and in quantum mechanics within the definition of Planck's constant. Angular momentum is the product of an object’s moment of inertia, in units of kg∙m and its rotational velocity in units of m∙s∙m, or simply s (i.e., Hz). This product of moment of inertia and rotational velocity yields kg∙m∙ s or the joule-second. Planck's constant represents the energy of a wave, in units of joule, divided by the frequency of that wave, in units of s. This quotient of energy and frequency also yields the joule-second (J∙s).