Calculate work, force, or distance using the physics formula W = F × d.
| Unit | Equal to |
|---|---|
| 1 kJ | 1,000 J |
| 1 cal | 4.184 J |
| 1 kcal | 4,184 J |
| 1 Wh | 3,600 J |
| 1 kWh | 3,600,000 J |
| 1 eV | 1.602 × 10⁻¹⁹ J |
In physics, work is done when a force causes an object to move in the direction of the force. It is measured in Joules (J) — the SI unit of energy. Work is a scalar quantity, meaning it has magnitude but no direction. The formula for work is W = F × d × cos(θ), where F is the applied force, d is the displacement, and θ is the angle between the force and the direction of motion.
Work and energy are closely related. When work is done on an object, it transfers energy to that object. This is known as the work-energy theorem — the net work done on an object equals the change in its kinetic energy. For example, pushing a box across a floor does work against friction, converting mechanical energy into heat.
Yes. When the force and displacement are in opposite directions, the angle θ is greater than 90°, making cos(θ) negative. For example, friction does negative work on a moving object because it opposes motion.
Work measures the total energy transferred, while power measures the rate at which work is done. Power = Work ÷ Time, measured in Watts (W). A powerful machine can do the same work as a weaker one, but in less time.
No. In physics, if there is no displacement, no work is done regardless of how much force is applied. For example, pushing against a wall with all your strength does no work if the wall does not move.