Work, Power & Energy — W = F·d·cosθ, P = W/t

Enter force, displacement, the angle between them, and time. We’ll compute work done, average power, and (optionally) efficiency using your input energy or power. Private by design — runs entirely in your browser.

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Tip: Press Ctrl/Cmd + Enter to calculate. URL updates so you can bookmark or share your inputs.

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Work, Power & Efficiency — Quick Primer

Work measures energy transferred by a force through a displacement along the force direction: W = F·d·cos(θ), where θ is the angle between the force and displacement. If θ = 0°, all the force is “along” the motion; if θ = 90°, the work is zero; if θ > 90°, the work is negative (energy leaves the object).

Average power over an interval is the rate of doing work: Pavg = W / t. Instantaneous power is P = \(\vec F \cdot \vec v\), but this tool focuses on the simple average.

Efficiency compares useful output to input. If you know the input energy supplied over the same interval, use η = W / Ein. If you know the input power instead, use η = Pavg / Pin. Values above 100% usually signal inconsistent inputs or unaccounted energy sources.

  • Units: Force (N), displacement (m), time (s), work (J), power (W), efficiency (%).
  • Signs: Negative work is possible (e.g., friction). The calculator reports it as-is.
  • Assumptions: Uses constant magnitudes over the interval and a single net angle θ.

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