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Chapter 9 of 28
Revision Notes

Work, Energy and PowerRevision Notes

BITSAT · Physics

Quick revision notes for Work, Energy and Power — key concepts, formulas, and definitions for BITSAT Physics preparation.

Revision Notes — Work, Energy and Power

Key concepts, formulas, and definitions from Work, Energy and Power for BITSAT Physics preparation.

Key Topics to Revise

1

Scalar Product and Mathematical Foundations

  • Scalar product of vectors A⃗ and B⃗ is A⃗·B⃗ = AB cos θ, where θ is angle between vectors
  • Scalar product gives the projection of one vector onto another
  • For unit vectors: î·î = ĵ·ĵ = k̂·k̂ = 1 and î·ĵ = ĵ·k̂ = k̂·î = 0
2

Work and Work-Energy Theorem

  • Work done W = F⃗·s⃗ = Fs cos θ, where θ is angle between force and displacement
  • Work is a scalar quantity and can be positive, negative, or zero
  • Positive work increases kinetic energy, negative work decreases it
3

Kinetic Energy

  • Kinetic energy KE = ½mv² for objects moving much slower than light
  • Kinetic energy is always positive (never negative or zero for moving objects)
  • KE depends on reference frame - same object has different KE in different frames
4

Work Done by Variable Force

  • For variable force F(x), work done W = ∫F(x)dx from initial to final position
  • Work done equals area under Force vs. displacement graph
  • For small displacement Δx, work done ΔW = F(x)Δx

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Key Concepts

The scalar product of two vectorsWork is defined as W =Kinetic energy is the energy possessedThe net work done onFor a variable force F(x)

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Frequently Asked Questions

What topics are covered in Work, Energy and Power for BITSAT?

Work, Energy and Power is an important chapter in BITSAT Physics. It covers key concepts and formulas that are frequently tested in the exam. Key topics include: Scalar Product and Mathematical Foundations, Work and Work-Energy Theorem, Kinetic Energy, Work Done by Variable Force.

Work, Energy and Power is a frequently tested chapter in BITSAT Physics. Questions from this chapter appear regularly in previous year papers. There are 51 practice questions available for this chapter.

Start by understanding the core concepts, then solve practice questions. Focus on formulas and their applications. Use revision notes for quick review before the exam.