Class 11 Physics Chapter 5 Work, Energy and Power – Revision Notes

Quick revision notes for Class 11 Physics Chapter 5 (Work, Energy and Power). These Class 11 Physics Chapter 5 notes are ideal for quick revision just before exams.

Key Formulas

• Work: W=Fd cosθ.
• KE=½mv²; Gravitational PE=mgh; Spring PE=½kx².
• Work-energy theorem: W=ΔKE.

Conservation of Energy

• KE+PE=constant (no non-conservative forces).

Collisions

• Elastic: momentum + KE conserved.
• Inelastic: only momentum conserved.

Power

• P=W/t=F·v; SI unit watt; 1 HP=746 W.

One-Line Summary

Work, energy, and power describe how forces transfer energy to bodies, with mechanical energy conserved in ideal (frictionless) systems and different collision types conserving momentum with or without kinetic energy.

Written by Satish

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