What Is Work in Physics?
In physics, work is the energy transferred to or from an object by a force acting through a displacement: W = ∫ F · dr. For a constant force along the displacement, W = Fd cosθ. SI unit: joule (J).
Work–energy theorem: the net work done on a particle equals the change in its kinetic energy, Wnet = ΔKE = ½m(vf2 − vi2).
Counter-intuitive cases: a centripetal force does zero work (perpendicular to motion). Carrying a box at constant height across a room does zero work against gravity. Holding a weight motionless requires muscular effort but does no physics work.
Recent research on this topic from arXiv
Preprints and papers indexed on arXiv.org. Links open the public abstract pages.
- Work-Energy theorem in rotational reference frames
D. M. Fernández, M. F. Carusela, C. D. El Hasi · 2010 ·arXiv:1101.0157v1
In standard textbooks of college physics, the Work Energy Theorem is usually presented for inertial frames of references and it is clear that energy is conserved when there is not net work of interaction forces. But what happens when energy... - Work and work-energy theorem in curved spacetime
Shaofan Liu, Liu Zhao · 2020 ·arXiv:2010.13071v3
The definitions of gravitational work as well as work done by the total external force on a massive probe particle moving in generic spacetime backgrounds are proposed. These definitions are given in the form of scalar integrals and thus, a... - Statistical work-energy theorems in deterministic dynamics
Chang Sub Kim · 2014 ·arXiv:1411.5101v4
We theoretically explore the Bochkov-Kuzovlev-Jarzynski-Crooks work theorems in a finite system subject to external control, which is coupled to a heat reservoir. We first elaborate the mechanical energy-balance between the system and the s...