Moments Topic Review summary

Key learning points

• Moment = force × perpendicular distance from the pivot line.
• Clockwise vs anticlockwise — assign a sign convention.
• Equilibrium: resultant force zero and resultant moment zero.
• Tilting: reaction at the losing contact becomes zero at the point of tipping.
• Uniform rods: weight acts at the midpoint.

Worked example 1 — Moment

10 N force, perpendicular distance 0.5 m.

Working

M=Fd_\\perp.

Worked example 2 — Equilibrium

Two conditions for a rigid body in equilibrium.

Working

Both needed in 2D.

Worked example 3 — Practice point 1

Apply this idea from the Topic Review: Moment = force × perpendicular distance from the pivot line.

Working

Attempt without notes, then check the answers PDF.

Worked example 4 — Practice point 2

Apply this idea from the Topic Review: Clockwise vs anticlockwise — assign a sign convention.

Working

Attempt without notes, then check the answers PDF.

Scaffolded Learning Sheet and answers (PDFs)

This page is a short, searchable overview for revision and search engines. Use the Scaffolded Learning Sheet first, then the Answers PDF for a full written solution. The printable PDFs remain the main classroom resource.