Physics
Work, Energy and Power: Concepts That Matter
By Dr. Sandhya Classes Editorial Team · Published 2026-10-03 · Updated 2026-10-03 · 3 min read
A clear guide to the work-energy theorem, conservative forces and power for Class 11, JEE and NEET.
Physics at Dr. Sandhya Classes is taught personally by Dr. Sandhya, Ph.D. in Physics, teaching since 2015 — offline in Zirakpur (Highland Marg & Lohgarh Road) and online across India. About Dr. Sandhya
Work depends on direction
Work is the dot product of force and displacement. A force perpendicular to motion does no work.
The work-energy theorem
The net work done on a body equals its change in kinetic energy. It often solves problems faster than Newton's laws.
Conservative forces and potential energy
Gravity and spring forces store energy that can be recovered; friction does not.
Power in real situations
Power is the rate of doing work. Questions on motors, lifts and vehicles test this idea.
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