## College Physics (4th Edition)

The total kinetic energy of the neutron and the pion is $40~MeV$ which is $6.4\times 10^{-12}~J$
We can find the mass $M$ that is lost: $1115~MeV/c^2 = 940~MeV/c^2+135~MeV/c^2+M$ $M = 1115~MeV/c^2 - 940~MeV/c^2-135~MeV/c^2$ $M = 40~MeV/c^2$ We can assume that the missing mass is converted into kinetic energy. We can find this energy: $E = Mc^2$ $E = (40~MeV/c^2)(c^2)$ $E = 40~MeV$ $E = (40~MeV)(\frac{1.60\times 10^{-13}~J}{1~MeV})$ $E = 6.4\times 10^{-12}~J$ The total kinetic energy of the neutron and the pion is $40~MeV$ which is $6.4\times 10^{-12}~J$.