Everyday we hear sounds from various

 sources like humans, birds, bells, machines,

 vehicles, televisions, radios etc. Sound is a

 form of energy which produces a sensation

 of hearing in our ears. There are also other

 forms of energy like mechanical energy, light

 energy, etc. We have talked about mechanical

 energy in the previous chapters. You have

 been taught about conservation of energy,

 which states that we can neither create nor

 destroy energy. We can just change it from

 ...