All About Torque!

Definition: Torque (τ) is the rotational equivalent of force, measuring a force’s effectiveness at causing an object to rotate around a pivot (like a door around its hinge). It depends on the magnitude of the applied force, the distance from the pivot (r), and the angle of application, with maximum torque occurring when force is perpendicular.

Key things to know:

• Equation:

  

• Units: Newton-meters (N⋅m)

• Sign Convention: Counterclockwise is positive, and clockwise is negative

• Maximizing Torque: Apply force far from the pivot (r is large) and perpendicular to the object (θ = 90 degrees, sin(90) = 1)

• Zero Torque: Force applied at the pivot (r = 0) or parallel/anti-parallel to the level arm (sin(0) = 0)

• Equillibrium: For a rigid body, ΣF = 0 and Στ = 0

• Rotation: Net torque causes angular acceleration (Στ = Iα)