A laser cavity includes two mirrors onc of them concave mirror with radius 86 cm and another one is convex with radius 1.42 m and the distance between two mirrors is 130 cm. The wavelength of this laser is 0.744 um. Show if the resonator of this laser is stable or not?

Ahypothetical metal has an orthorhombic unit cell for which the a, b, and c lattice parameters are 0.413 nm, 0.665 nm, and 0.876 nm, respectively. (a) if there are 8 atoms per unit cell and the atomic packing factor is 0.536, determine the atomic radius (in nm). (b) if the density is 3.99 g/cm3, calculate the metal's atomic weight (in g/mol).