Mechanical energy transfer
What is work in physics?
Work is the energy transferred when a force moves an object through a distance. The simple formula applies when the force acts parallel or opposite to the displacement.
Formula
Work formula
WorkW = F × d
- W is work in joules.
- F is force in newtons.
- d is distance in meters.
Worked example
A 20 N force moves an object 5 m
- Write the formula: W = F × d.
- Substitute the values: W = 20 × 5.
- Calculate the work: W = 100 J.
Rearranged equations
Solve for force or distance
Force
F = W ÷ d
Divide work by a positive distance.
Distance
d = W ÷ F
Divide work by a non-zero force. Work and force must have matching signs.
Direction and signs
Positive, negative, and zero work
Work is positive when force acts in the direction of displacement and negative when force acts opposite to it. Work is zero when the force is zero or when there is no displacement.
Units
Standard SI units
Use newtons for force and meters for distance. Convert other units before entering values.
One joule1 J = 1 N·m
Calculation limits
Important assumptions
- Distance must be greater than zero.
- Force may be positive, negative, or zero when calculating work.
- Force cannot be zero when calculating distance.
- The formula assumes force is parallel or opposite to displacement.
- The calculator does not automatically convert units.
Related tools
Continue analyzing mechanics
Use the Force Calculator to solve force, mass, or acceleration.
Use the Kinetic Energy Calculator to calculate motion energy, or use the Momentum Calculator for mass and velocity problems.
Questions and answers
Work calculator FAQ
What formula does the work calculator use?
It uses W = F × d for a constant force acting parallel or opposite to the displacement.
What is the SI unit of work?
The SI unit of work is the joule, written as J. One joule equals one newton-meter.
Can work be negative?
Yes. Work is negative when the force acts opposite to the displacement.
Can distance be negative?
This calculator uses positive distance magnitude. Direction is represented by the sign of the force and work.