Moments in 2D and 3D

• What is a moment?


  When a force is applied to an object it will produce a tendency for the body to rotate
• What is the equation of the magnitude of a moment at a certain point?

  Force x perpendicular distance
• How is the direction of a moment found?

  The direction of a moment is defined by its moment axis which is perpendicular to the plane that contains the force and the moment arm
• What rule is used to find the direction of a moment?

  The right hand screw rule: thumb points in the direction of the moment axis, fingers point in the direction of the moment arm

  Anticlockwise/out of page = positive

  Clockwise/into page = negative
• What is a couple?

  Two forces, equal in magnitude, parallel but opposite in direction