Be able to calculate the moment of a force about an axis through a point in the plane of the body.

For coplanar forces, moments may be described as being about a point.

[Understanding of the vector nature of moments is excluded.]

Parallel and non-parallel coplanar forces

Understand that when a rigid body is in equilibrium the resultant moment is zero and the resultant force is zero.

Equilibrium of rigid bodies

Be able to use moments in simple static contexts.

e.g. To determine the forces acting on a horizontal beam or to determine the forces acting on a ladder resting on horizontal ground against a vertical wall.

Questions will be set in which the context of the problem can be modelled using rectangular laminas, uniform and non-uniform rods only.

Learners may assume that:
1. for a uniform rod the weight acts at the midpoint of the rod,
2. for a non-uniform rod the weight acts at either a specified given point or is to be determined by moments,
3. for a rectangular lamina the weight acts at its point of symmetry.

Equilibrium of rigid bodies Parallel and non-parallel coplanar forces