Using the half-lives for 238U and 235U, the natural abundance of each isotope, and knowing the density of uranium metal is 19.2 g/cm3, calculate the total decay rate (disintegrations per second) of uranium atoms in a solid sphere, 10 cm in diameter. Both 238U and 235U decay by alpha emission. The alpha particle energies are approximately 4.3 MeV and 4.7 MeV, respectfully. There is additional energy released in photons (gammas) and subsequent decay of daughter products. Ignoring all that, using only the primary alpha particle energies, calculate the heat generated in the sphere of uranium in watts.