- A Few Ev 25 P45 In A Location In Outer Space Far From All Other Objects A Nucleus Whose Mass Is 3 894028 X 10 25 Kg 1 (305.82 KiB) Viewed 21 times
a few ev. -25 ••P45 In a location in outer space far from all other objects, a nucleus whose mass is 3.894028 x 10-25 kg and that is initially at rest undergoes spontaneous alpha decay. The original nucleus disappears, and two new particles appear: a He-4 nucleus of mass 6.640678 x 10-27 kg (an alpha particle consisting of two protons and two neutrons) and a new nucleus of mass 3.827555 x 10 kg. These new particles move far away from each other, because they repel each other electrically (both are positively charged). Because the calculations involve the small difference of (comparatively large numbers, you need to keep seven significant figures in your calculations, and you need to use the more accurate value for the speed of light, 2.99792e8 m/s. Choose all particles as the system. Initial state: Original nucleus, at rest. Final state: Alpha particle + new nucleus, far from each other. (a) What is the rest energy of the original nucleus? Give seven significant figures. (b) What is the sum of the rest energies of the alpha particle and the new nucleus? Give seven significant figures. (c) Did the portion of the total energy of the system contributed by rest energy increase or decrease? (d) What is the sum of the kinetic energies of the alpha particle and the new nucleus?