2. Balancing Forces and Torques

• 2.1 Motivation and outline: forces are vectors
• 2.2 Sets
• 2.3 Groups
• 2.4 Fields
• 2.5 Vector spaces
• 2.6. Physics application: balancing forces
• 2.7 The inner product
• 2.8 Cartesian coordinates
• 2.9 Cross products — torques
• 2.10 Worked example: Calder's mobiles
• 2.11 Problems
• 2.12 Further reading

---

2.6 Physics application: balancing forces