Instantaneous rotational power is torque times angular velocity about a common axis.
Difficulty
Intermediate
Read time
5 min
Prerequisites
Basic algebra, consistent units, and the stated model assumptions
Source
OpenStax, College Physics 2e, §10.4 (Paul Peter Urone and Roger Hinrichs)OpenFormulaGraph equation reference; FormuLab adaptation details and license are provided below.
Adapted from OpenFormulaGraph, under CC BY 4.0.
FormuLab adapted wording, notation, applicability conditions and topic placement, and expanded the numerical check into a worked example. The textbook section reference was corrected.
Instantaneous rotational power is torque times angular velocity about a common axis. Opposing torque and angular velocity give negative power, representing energy removed from the rotation.
| Symbol | Meaning | Units |
|---|---|---|
| Power (rotational) | ||
| Torque | ||
| Angular Velocity |
Relate instantaneous torque and angular speed.
Compare power at different operating speeds.
A shaft turns at +2 rad/s while a +5 N·m torque acts on it. Find the instantaneous power transferred.
OpenFormulaGraph equation reference; FormuLab adaptation details and license are provided below.
Adapted from OpenFormulaGraph, under CC BY 4.0.
FormuLab adapted wording, notation, applicability conditions and topic placement, and expanded the numerical check into a worked example. The textbook section reference was corrected.
Assumptions
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