Work energy and power

Work is the action of force moving an object. It is a measure of energy transfer. Work=force×distance. The SI unit for work is the joule, equivalent to Nm.
Work can also be measured in kilowatt hour since joule is very small quantity of work. One kilowatt hour is the amount of work done by a machine with a power of 1kW in 1h. 1kW∙h=3600000J=3.6MJ
Energy is the ability to do work and is measured in joules.
The energy due to position or elevation is called gravitational potential energy (PE orE_g ) and is calculated from: E_g=mgh.
Kinetic energy (KE or Ek) is the energy of a moving object. The kinetic energy of an object depends on its mass and its speed or velocity, i.e. E_k=1/2 〖mv〗^2
Total mechanical energy (ET or TME) is the sum of the kinetic and potential energy and it is constant at all points of a falling or moving body. E_T=E_g+E_k
The law of conservation of energy states that: “In any transfer or transformation of energy, the total amount of energy remains constant”.
In a nuclear reaction, so much energy is released, hence violating the law of conservation of energy. This is explained in the theory of relativity established by Albert Einstein in 1905, stating that: “a decrease in mass of a system might show up as an increase in the energy of the system”. So mass is another form of energy. That energy is calculated from : E=mc^2
Power is the rate at which the work is done i.e. Power=(work done)/(time taken). The SI unit of power is the watt, equivalent to the joule per second.