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Energy Work calculator
Calculate the work done by a force, or solve for the force, distance or power involved.
Energy Work calculatorEnergy Work
W = F·d·cosθ · Power · Efficiency Analysis
W = F × d × cos(θ) | Power P = W/t | θ = angle between force and displacement
The work-energy theorem is one of physics' great shortcuts: the work done on an object equals its change in kinetic energy, whatever complicated path the forces took. This calculator applies it directly, solving for work, speeds or mass.
How to use this calculator
- Enter the mass of the object.
- Enter its initial and final speeds.
- Press calculate to see the work done (the kinetic energy change).
Why the theorem bypasses the details
Forces that vary, curves and rough surfaces make step-by-step force accounting miserable. Energy ignores the route and compares only the endpoints, which is why engineers reach for it first and use force methods to fill in what energy cannot say, like times and accelerations.
Frequently asked questions
What is the work-energy theorem?
Net work done on an object = final kinetic energy − initial kinetic energy = ½mv² − ½mu².
Can work be negative?
Yes. Braking and friction do negative work, removing kinetic energy. The theorem handles it naturally: the change is negative.
Does the theorem include potential energy?
In its wider form, yes: work by non-conservative forces equals the change in total mechanical energy. The kinetic-only version here assumes gravity and springs are counted inside the work or absent.