Explain why the perpetual motion machine of the first kind is impossible

The first law of thermodynamics establishes an exact relationship between heat and work . According to it a definite quantity of heat will produce a definite amount of work and vice versa. It denies that work or energy can be created out of nothing.   It means that it is impossible to construct a thermal machine which may operate without any expenditure of fuel and may thus create energy out of nowhere. A machine that would so this could run itself and is generally called a perpetual motion machine of the first kind. The first law rules out such mechanics and is therefore sometimes defined in the form, " Perpetual motion machine of the first kind is impossible ". The fact that no exception to the first law has been found yet and no one has succeeded in building such a machine forms an experimental basis for the first law. Three ideas are included in first law of thermodynamics :
1) Heat is a form of energy in transit.
2) Conservation of energy takes place in thermodynamic systems.
3) Ever system in equilibrium , possesses an internal energy which is a function of state,i.e., depends only upon the initial and final states of the system.