Work
Summary
- Work defined
- Work is done whenever a force results in a displacement.
W = F∥∆s
The component of the force parallel to the displacement (F∥) is what matters. - Work is the scalar product of force and displacement.
W = F∆s cos θ
- Work is the force-displacement path integral.
W = ⌠
⌡F ⋅ ds
- Work is done whenever a force results in a displacement.
- Work-energy theorem
- Work is done when the energy of an object changes form (energy transduction).
- Work is done when energy is transfered from one system to another (energy transfer).
- Work is a change in energy.
abbreviated version W = ∆E algebra version F∆s cos θ = ∆E calculus version ⌠
⌡F ⋅ ds = ∆E - Units
- The SI unit of work and energy is the joule, named after the English physicist and brewer James Joule (1818–1889).
[J = N m = kg m2/s2]
- The electronvolt is an acceptable non SI unit of energy. It is used for some applications in electromagnetism; solid state, atomic, nuclear, and particle physics; and related sciences like biophysics, chemistry, and astronomy. An electron volt is the work done a particle with one elementary charge when it is moved between two points with a potential difference of one volt. It is described in more detail in the section on electric potential (a.k.a. voltage).
1 eV = (1.6 × 10−16 C)(1 V) = 1.6 × 10−16 J
- The SI unit of work and energy is the joule, named after the English physicist and brewer James Joule (1818–1889).