Question

State and prove the law of conservation of energy?

Answer 1

in a process if a work is done, the total internal energy before and after the work should be the same and the energy can't be neither created nor destroyed but can be converted into other forms of energy

think if a bomb explods the energy before explosion is
potential energy( x)
and after the explosion is converted to kinetic energy(k) and sound energy(Q)

according to law of conservation of energy x=k+Q

hope it helps