Torque from a Force ?

The force F (blue) is split into two parts, shown as a right triangle: the gray dashed leg along the lever is F∥ = F cos θ — a stabilizing component when θ > 90° or a distracting component when θ < 90°, since it doesn't turn the lever; the thick red leg is F⊥ = F sin θ, the rotational component that actually turns the lever. As θ approaches 0° or ±180°, watch the red leg shrink to nothing even if F stays large. Drag the blue line to rotate the force, or drag its arrowhead to change its strength.