CBSE Class 9 Physics Work and Energy
WorkWork is done when a force acting on a body produces displacement in it.
Work is a scalar quantity and its SI unit is joule.
Work done is positive if the angle between force and displacement is acute and negative if the angle between them is obtuse.
EnergyAn object having a capability to do work is said to possess energy.
The energy possessed by a body by virtue of its motion is called kinetic energy.
The energy possessed by a body by virtue of its position or change in configuration is called potential energy.
Power is the rate at which work is done.
Conservation of Energy and PowerThe change of one form of energy into another is called conversion/transformation of energy.
Law of conservation of energy states that energy can neither be created nor be destroyed but can be transformed from one form to another.