What is energy?
Energy is defined us the ability of a body to do work.We can also call that energy is 'stored work'.The energy is never lost;that is converted from one form to another.Peoples realized this hundreds of years ago and wanted to build perpetual motion machines-machines that keep moving without any input of energy.They have not succeeded yet.Today,we talk a lot about saving energy.This means effects to be made to reduce energy consumption.
Is energy conserved?
The energy can neither be created nor be destroyed;it can be converted from one form to another.For instance,when we draw a bow,we put energy in it.This energy is converted into the energy of movement called kinetic energy when we shoot the arrow.Then for example,if you take a stone,you should give a energy to that stone.his kind of energy is also called potential energy gets stored in it.Otherwise the stone is fallen down,it can do some work by hitting and damaging object.
If energy is conserved,who do we need to save energy?
Energy is conserved we should try to save it,in every time energy is transferred or transformed,some of it is lost.In every time some work is done,energy is released in the form of heat through friction.Although heat is a form of energy,we cannot use it to generate electricity or make a car go.Most of it gets radiated and is not available for use.For this reason,we need to save fossil fuels such as crude oil and coal,which are sources of energy and are scarce.
Where does all energy come from?
All of the energy are coming from the sun.Plants convert the energy from the sunlight into food substances through photosynthesis and animals eat plants.The plants will store the solar energy.Crude oil and coal formed from the remains of dead animals.Where does the sun get all its energy from?At the sun'core,atomic nuclei fuse together at extremely high temperatures.As a result of this fusion enormous radiation energy is released.Its energy seems to be unlimited.But this is not the case;our sun will dead one day.we use its energy in the form of hydro or wind power,coal,crude oil,or biogas.
What is a perpetual motion machine?
For centuries,scientists have been trying to build a perpetual motion machine:a machine that once started continues to move for ever and also does work while moving.The idea behind this is to usefully apply the fact of conservation of energy.Robert Fludd,for instance,developed an apparatus in which a wheel is driven by water falling from a high tank.The wheel pumps water up again,thereby driving a grindstone.He overlooked the fact that because the components rubbed against one another,the energy of friction was lost to the air as heat.
Do we save energy while sleeping?
Although there is no movement when we are asleep,our body consumes some amount of energy.We need this energy because the brain,the heart,and other organs keep working even when we are asleep.This energy comes from the food we eat and is measured in calories.The number of calories in different foods is different.People doing hard physical labour need more calories than people who don,t.Marmots use this trick,for instance,in winters.They have a winter sleep of one month,during which they consume very little energy.They can thus live on the food eaten earlier and can also survive at places where food is scarce because of frost and snow.
0 Comments
If you have any doubts,please inform me.