Work, Energy and Power

What this topic covers

Concept of work as a measure of energy transfer (unit joule (J)). Concept of energy as capability to do work (unit joule (J), KWh for electrical consumption). Work done in a gravitational field (lifting a body and by falling bodies). Types of mechanical energy (Potential energy (P.E.) and Kinetic energy (K.E.), derivation of P.E. and K.E. expected to be known, identification of types of energy possessed by a body under given conditions). Conservation of mechanical energy and its verification. Concept of power as time rate of doing work (unit watt (W)). Application of mechanical energy-machines: Levers, pulleys, inclined plane, wedge, screw, wheel and axle, gears. Treatment of force ratio (F.R), mechanical advantage (M.A), velocity ratio (V.R) and efficiency of each machine. Identification of simple machines within complicated machines (e.g., bicycle). Effects of friction on machines and methods of reducing it.