Physics · Class 11 · Chapter 5
Work, Energy and Power
10 lessons106 min8 simulations9 practice questions
This chapter gives an energy-based way to solve mechanics problems. Using the scalar product, it defines work, links work to kinetic energy through the work-energy theorem, introduces potential energy for conservative forces (gravity and springs), states when mechanical energy is conserved, defines power, and applies momentum and energy ideas to collisions.
Also called: work energy theorem · conservation of energy · collisions
Lessons
10 lessons · 106 min
01The scalar productNCERT § "The Scalar Product"6 min02WorkNCERT § "Work"11 min1 sim03Kinetic energy and the work-energy theoremNCERT § "Notions of Work and Kinetic Energy: The Work-Energy Theorem"7 min04Work done by a variable forceNCERT § "Work Done by a Variable Force"9 min1 sim05Potential energy and conservative forcesNCERT § "The Concept of Potential Energy"10 min1 sim06Conservation of mechanical energyNCERT § "The Conservation of Mechanical Energy"14 min2 sims07Potential energy of a springNCERT § "The Potential Energy of a Spring"10 min1 sim08PowerNCERT § "Power"10 min1 sim09CollisionsNCERT § "Collisions"12 min1 sim10Chapter reviewMust-know facts, traps and formulas17 min
Simulations
8 in this chapter
Work: only the part of the force along the motion countsIn: WorkWork is the area under F–xIn: Work done by a variable forceSame ends, different pathsIn: Potential energy and conservative forcesWhere does the energy go on a rough patch?In: Conservation of mechanical energyRound a vertical circleIn: Conservation of mechanical energyA spring stores ½kx², the area under its F–x lineIn: Potential energy of a springPower and speed: P = FvIn: PowerCollisions: momentum always survives, kinetic energy may notIn: Collisions