Energy
Hey guys, in this article we are going to learn most interesting and essential article, i.e. energy. Just think on the following examples 1) what make possible for us to see the things around? 2) What is factor involved in cooking of food using gas burner? How athletes can manage practice of running, jump or any other events for long time? Answers of this entire question are related to energy. In first case it is light energy, in second case it is heat energy whereas in third case it’s the energy stored in muscles. So what exactly energy is? Let us define it.
Energy is capacity of doing the work. Energy is available in different forms around us. For performing certain amount of work, the same amount of energy is necessary. Hence energy is always equivalent to work.
SI unit of energy is also taken as joule (J). Sometimes energy is also calculated in terms of calories (cal). 1 kcal= 1000 kilocalorie.
When we eat a food, different contents present in food like protein, vitamins, minerals etc provides energy to our body. This energy stored in our body is used by us to do daily work. Similarly heat energy, light energy and many more other forms of energy helps us to do the work which cannot be completed by the energy present in body alone. Earth exerts gravitational potential energy on us by which we are bounded to earth surface.
Energy has one very important characteristic that it is inter convertible. Eg. Electric energy can be converted in to heat energy in electric iron, electric heater as well as in to light energy by bulb. Chemical energy in fuels like petrol and diesel is very essential in transport system. We have used this characteristic of energy very wisely to make our life more comfortable.
Like work, one can calculate energy as per work;
Ex: 1) Find the energy required to move an object of weight 500 N by 5 m.
Ans: Here, F=500 N, s=5 m
Energy required is nothing but the work done,
W= F.s=500×5=2500 J
Hence required energy will be 2500 J