Topic 1 · pp. 106–108 · Free
Topic Notes · Easy summaries with diagrams
Chapter 5 — Chapter 5 — Work, Energy and Power
0 of 7 steps done ✓ (5 topics + Exercise + Numericals)
Topic 1 of 5
📘Easy summary
Work is done when a force moves a body in its direction: W = Fd cos θ, θ = angle between force and displacement. Scalar; unit joule (1 J = 1 N × 1 m = 1 kg m² s⁻²). Maximum at θ = 0°, zero at θ = 90° or if no displacement (pushing a wall, man rowing upstream at rest relative to shore). Area under force-displacement graph = work.
⭐Key points
- Lifting through h: W = mgh.
🔬Diagram
🌿Real-life example
20 N at 60° over 3 m: W = 20 × 3 × 0.5 = 30 J.
💡Exam tip
- Use component along motion.
✅Quick check
1. Work zero when θ =
2. 1 J =
Practice this chapter
Lock it in with flashcards and exam-style MCQs.