The first question is what is Energy?

The capacity of dowing work is known as energy . And different types of energy have different type of power (at end definition of power are written ) .

Who discover Energy?

In 1802 lectures to the Royal Society, Thomas Young was the first to use the term “energy” in its modern sense .

SI unit of energy is joule ( j ).

Common forms of energy include the kinetic energy of a moving object, the potential energy stored by an object’s position in a force field (gravitational, electric or magnetic), the elastic energy stored by stretching solid objects, the chemical energy released when a fuel burns, the radiant energy carried by light, and the thermal energy due to an object’s temperature. But here we don’t talk about this form of energy no we talk about how this energy travel or transfer like sunlight which travel from space but space is empty the how could it travel ,,hmm in about 16 -17 century the scientist thought that space have also a medium called ether. But they were wrong because light is electromagnetic radiation which doesn’t need medium to travel anyway we are talking about travel or transfer of energy , energy need medium to travel or transfer how

Energy trave in the form of wave like sound wave . Yeah sound ,sound are formed by osilation or vibration of any object . When an object vibrate it vibrate also particles this partical pass vibration and it comes to our ear drums.

Some formulas

Energy is strictly conserved and is also locally conserved wherever it can be defined. In thermodynamics, for closed systems, the process of energy transfer is described by the First law other laws we discuss at next blog.

E=W+Q

where E is the amount of energy transferred, W represents the work done on the system, and Q represents the heat flow into the system. As a simplification, the heat term, Q, is sometimes ignored, especially when the thermal efficiency of the transfer is high.

E=W

This simplified equation is the one used to define the joule, for example.

Definition

Power

power is the amount of  energy transferred or converted per unit time.the unit of power is the watt, equal to one joule per second. In older works, power is sometimes called activity.

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