Torque is the turning effect of a force about a pivot: τ = r·F·sinθ. Drag the sliders below to change the applied force, the distance from the pivot and the angle, and watch the torque and the lever arm respond in real time.
The identical applied force F can produce zero turning effect or the largest turning effect this simulator allows, and nothing but the angle θ decides which. Hold F and the distance r fixed, then sweep θ from 0° upward: the torque τ readout climbs from nothing to its peak at 90°, then falls back to zero by 180°. Same force, opposite outcomes.
What the angle slider is really tracking is the lever arm readout, r·sin(θ) — the perpendicular distance from the pivot to the force's line of action. Only the perpendicular slice of the force, F·sin(θ), does any turning; the part aimed straight along the arm is wasted, which is why pushing directly toward the pivot spins the object not at all. This kills the intuition that a big force must mean a big torque. Feed in a large F at θ near 0° and watch τ = r·F·sin(θ) stay pinned near zero.
Then work the other two sliders: doubling F doubles τ, and doubling r doubles it too, because torque rides on the lever arm, not force alone — the reason a longer wrench frees a stubborn bolt. Put numbers to your own bolts with the torque calculator, or wander the rest of our tinker-and-see physics sandbox shelf.
Torque is the turning effect of a force about a pivot: τ = r·F·sin(θ), where F is the force, r the distance from the pivot, and θ the angle between them. Equivalently it is the force multiplied by the perpendicular lever arm r·sin(θ).
When the force acts at right angles to the arm (θ = 90°, so sin θ = 1). The torque falls to zero when the force points straight along the arm, toward or away from the pivot (θ = 0° or 180°), because then it has no turning effect at all.
Because torque grows with the distance r. A longer spanner gives a longer lever arm, so the same effort at the end produces more torque at the bolt. Doubling the length doubles the torque for the same force.
No. Torque also depends on the distance and the angle. A large force aimed straight at the pivot produces zero torque, while a smaller force applied far out and at a right angle can produce much more. Only the perpendicular part of the force turns the object.