Work & Energy Calculator
Calculate the work done by a force acting at an angle over a distance, using W = F·d·cosθ.
How it works
W = F·d·cosθ · power P = W / t
Work is energy transferred when a force moves an object, equal to the force times the distance times the cosine of the angle between them. Only the component of force along the motion does work: push straight ahead (0°) and all of it counts; push sideways (90°) and cosθ is zero, so no work is done however hard you push. A force opposing the motion (angle above 90°) does negative work, removing energy. Divide the work by the time and you get the average power.
Worked example
Pushing with 100 N over 8 m in the direction of motion (0°) does W = 100 × 8 × cos0° = 800 J. If it took 4 s, the average power is 800 / 4 = 200 W, about 0.27 hp.
Sources: Work (physics) — Wikipedia
Frequently asked questions
Why does angle matter?
Only the part of the force aligned with the motion does work, and cosθ picks out that component. Perpendicular forces (90°, cosθ = 0) do no work — which is why carrying a bag horizontally does no work against gravity even though it feels tiring.
Can work be negative?
Yes. When the force opposes the motion — angle greater than 90° — cosθ is negative, so the work is negative. Friction and braking do negative work, taking kinetic energy out of the object.
How is work related to power?
Power is the rate of doing work: P = W/t. The same 800 J done in 4 s is 200 W; done in 2 s it would be 400 W. Work is the energy; power is how fast you deliver it.
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Educational estimate. Check the formula and units for your exact case.