✓ Sources checked · 10 September 2026 · View verification
Torque is the turning effect of a force, measured about a chosen point or axis. Net torque changes angular momentum; steady fixed-axis rotation does not inherently require a continuing net torque.
By Matan · Updated
A precise lever arm
τ = rF sin θ = Fdperp. The perpendicular moment arm is the distance from the axis to the force’s line of action, not always simply the handle length. Torque and power differ: rotational power is τω. [1]
Worked fixed-axis acceleration
A rigid wheel with inertia 0.50 kg·m² experiences net torque 2.0 N·m about its fixed symmetry axis. Angular acceleration is τ/I = 4.0 rad/s². Starting from rest under that constant torque, after 3.0 s it reaches 12 rad/s and turns through 18 rad. Work is τθ = 36 J, matching final energy ½Iω² = 36 J.
Torque without motion
You can apply torque to a stuck lid while an opposing torque balances it. Conversely, an ideal freely rotating wheel can continue turning with zero net torque. Both facts follow from the net-torque condition rather than the presence or absence of rotation alone.
Wheel torque is not an entire vehicle specification
Gearing, angular speed, wheel radius, losses and available traction connect engine torque to vehicle behaviour. A longer tool changes leverage but does not create energy. The worked wheel assumes rigid fixed-axis motion and negligible losses.
Continue learning
How this article was checked
Sources checked; calculations checked where shown. The definitions, model assumptions and main explanatory claims were cross-checked against the sources below. Worked-example arithmetic and units were checked separately. These examples are illustrative calculations, not experimental measurements.
Source cross-check and editing assisted by AI. No independent human scientific review is recorded for this revision. The check applies to the version dated 10 September 2026; it is not a guarantee that every possible interpretation is correct.
Report an issue or request a fact-check · Editorial standards
Sources and further reading
- OpenStax: Torque — Torque.
- OpenStax: Rotational inertia — Rotational inertia.
- OpenStax: Rotational work and power — Rotational work and power.
Cite this article
Matan. “Torque: The Turning Effect of a Force.” Your Physicist. Originally published 2026-06-11; updated 2026-09-10. https://your-physicist.com/torque-the-hidden-force-of-rotation/
Revision history
: Corrected the claim that rotation always needs torque; added matching angular-motion and energy calculations. Added linked sources and a transparent verification record.
