Forces summary

Key learning points

• Resolve horizontally/vertically or parallel/perpendicular to a plane.
• Weight $mg$ acts vertically downward.
• Friction $F\le\mu R$, with equality when limiting.
• Equilibrium means zero resultant in each direction.

Worked example 1 — Slope component

Component of weight down a smooth plane at angle $\alpha$?

Working

The perpendicular component $mg\cos\alpha$ balances the normal reaction.

Worked example 2 — Resolve horizontally/vertically or parallel/perpendicul

Use this method from the Forces sheet: Resolve horizontally/vertically or parallel/perpendicular to a plane.

Working

Each key learning point matches a question type on the printable worksheet.

Worked example 3 — Weight acts vertically downward

Use this method from the Forces sheet: Weight $mg$ acts vertically downward.

Working

Each key learning point matches a question type on the printable worksheet.

Worked example 4 — Friction , with equality when limiting

Use this method from the Forces sheet: Friction $F\le\mu R$, with equality when limiting.

Working

Each key learning point matches a question type on the printable worksheet.

Worked example 5 — Equilibrium means zero resultant in each direction

Use this method from the Forces sheet: Equilibrium means zero resultant in each direction.

Working

Each key learning point matches a question type on the printable worksheet.

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.