This paper analyzes the quantities of energy and momentum in the definitional relationship of relativistic mechanics, in the de Broglie momentum hypothesis and in the Klein-Gordon, Dirac and Schrodinger equation. The results of analysis show that Planck constant and relativistic relationships on the length contraction and increase in mass are a reflection of the same physical principles in nature, that instead of identifying wavelength l as the wave of matter in the de Broglie hypothesis h/l=mv this must be connected with the real dimension of particle lo with the rest state value h/lo= moc= hfo/c and that on this basis we can come to the fundamental equations of quantum mechanics that are the Klein-Gordon, Dirac and Schrodinger equation without the necessity of the wave functions. The results of analysis show that energies in relativistic mechanics as mc², mvc, moc² and energy of a photon hf do not represent quantity of energy, but quantity of momentum multiplied by c, so mc.c, mv.c, moc.c, hfo/c.c and merely the dimension of such quantities equals in dimension the quantity of energy.
