Question

explain total energy with three examples.

Answer 1

In physics, energy is the quantitative propertythat must be transferred to an object in order to perform work on, or to heat, the object.[note 1] Energy is a conserved quantity; the law of conservation of energy states that energy can be converted in form, but not created or destroyed. The SI unit of energy is the joule, which is the energy transferred to an object by the work of moving it a distance of 1 metre against a force of 1 newton.
In physics, energy is the quantitative propertythat must be transferred to an object in order to perform work on, or to heat, the object.[note 1] Energy is a conserved quantity; the law of conservation of energy states that energy can be converted in form, but not created or destroyed. The SI unit of energy is the joule, which is the energy transferred to an object by the work of moving it a distance of 1 metre against a force of 1 newton.

Answer 2

Answer:

The work-energy principle states that an increase in the kinetic energy of a rigid body is caused by an equal amount of positive work done on the body by the resultant force acting on that body. Conversely, a decrease in kinetic energy is caused by an equal amount of negative work done by the resultant force.

Examples,  

(1) A car is accelerating constantly. Here velocity is increasing. As a result of, kinetic energy is also increasing. So positive work is done.

(2) A ball is dropped from a certain height. Here velocity of the ball is increasing gradually due to gravitational acceleration. As a result of which kinetic energy increases and positive work is done.

(3) A motor bike applies break and comes into rest after few second. Here work done by the break is negative. Because speed decreases, for which K.E also decreases