Engine in thrust. Particularly notable kinds of engines include: Engine An engine or motor is a machine designed to convert one form of energy into mechanical energy. Heat engines burn a fuel to create heat which is then used to do work. Internal combustion engines are heat engines that burn fuel in a combustion chamber to extract work from the pressure of expanding gases. Electric motors convert electrical energy into mechanical motion; pneumatic motors use compressed air; and clockwork motors in wind-up toys use elastic energy. In biological systems, molecular motors, like myosins in muscles, use chemical energy to create forces
Potential energy of protein a spring connecting the atoms together. Total potential energy based on bond length is over set S set of pairs of atoms that are connected by chemical bond defined as; E = Σ k(α-α) where: k is the force constant α is the equilibrium length α is the current length for the bond between ith and jth atoms. Just as the potential energy can be written as a quadratic form in the internal coordinates, so it can also be written in terms of generalized forces. The resulting coefficients are termed compliance constants. Like bond length, when three atoms are connected