A $10.0 \mathrm{g}$ iron bullet with a speed of $4.00 \times 10^{2} \mathrm{m} / \mathrm{s}$ and a temperature of $20.0^{\circ} \mathrm{C}$ is stopped in a $0.500 \mathrm{kg}$ block of wood, also at $20.0^{\circ} \mathrm{C},$ which is fixed in place. (a) At first all of the bullet's kinetic energy goes into the internal energy of the bullet. Calculate the temperature increase of the bullet.
(b) After a short time the bullet and the block come to the same temperature $T$. Calculate $T$, assuming no heat is lost to the environment.