Nuclear fusion, the energy source of the Sun, hydrogen bombs, and fusion reactors, occurs much more readily

Question:

Nuclear fusion, the energy source of the Sun, hydrogen bombs, and fusion reactors, occurs much more readily when the average kinetic energy of the atoms is high—that is, at high temperatures. Suppose you want the atoms in your fusion experiment to have average kinetic energies of 6.40 × 10^-14 J. What temperature is needed?