1. Torque

1.0  Torque

Definition: A Torque is defined by the force F applied at the distance r from the pivot point. It is the “turning push” that makes something rotate. Think of opening a door, pushing near the hinge is hard, but pushing at the far edge is easy. The effect depends on the followings;

    1. how hard you push (force  ),
    2. how far from the pivot (distance  ),
    3. and the angle of your push.

Quantitatively, torque about a point is given as
where   is the angle between the force and the line from the pivot to the point of application.
Units: newton‑meter (N·m).

Calculations Examples:

1.      A force of 50 N is applied perpendicular to a spanner 0.4 m long. Calculate the torque.

2.      A person pushes a door with a force of 25N at a point 0.8 m from the hinges. The force is perpendicular to the door. Find the turning moment

3.      A force of 60 N acts on a wrench 0.5 m long at an angle of 30° to the handle. Calculate the torque.

4.      A mechanic needs to produce a torque of 120 N·m using a spanner 0.6 m long. The force is applied at 90°. Find the force required.

5.      A force of 80 N produces a torque of 32 N·m. Find the perpendicular distance from the pivot.