<p> Solving Static Equilibrium problems involving rotation (Torque)</p><p>Torque is a Force which acts at a distance and causes a rotation. T = Fxd where the force is perpendicular to the distance d.</p><p>In static equilibrium;</p><p>Fx = 0 (Forces in x – direction must add to 0) Fy = 0 (Forces in y – direction must add to 0) To = 0 (Torques about any point o must add to 0)</p><p>The Torque idea is new, here are a few key ideas. 1. Choose a location to treat as the pivot or 0 point. Any point is valid 2. Typically you choose a 0 point where a force is “applied”, that way the torque from that force = 0 (because the distance = 0) 3. Choose a direction for positive torque (say Clockwise rotation is positive). Then force causing counterclockwise rotation are negative torques. 4. If a force acts at an angle, only use the amount of the force which is perpendicular to the distance d. (resolve the force in parallel and perpendicular components, only the perpendicular part causes torque or rotation.) 5. If there are horizontal and vertical forces remember that these need to balance in both directions. </p>