Determine el cambio en la energía interna en el proceso de fusión de un cubo de hielo de 12 g y cuya temperatura inicial es 0˚C

Light from a sodium lamp passes through a diffraction grating that has 1000 slits per millimeter. the interference pattern is viewed on a screen 1.000 m behind the grating. the first (m = 1) two bright yellow fringes that are visible are 0.7288 m and 0.7300 m from the central maximum. what are the wavelengths of these two fringes?