Answer
360 m/s
Work Step by Step
The kinetic energy first heated the bullet to the melting temperature, and then liquefied it.
$$\frac{1}{2}mv^2=Q_{heat}+Q_{melt}$$
$$\frac{1}{2}mv^2=mc\Delta T+mL$$
$$\frac{1}{2}(0.0062kg)v^2=(0.0062kg) (\frac{130J}{kg\cdot C^{\circ}})(327^{\circ}C-20^{\circ}C)+ (0.0062kg) (0.25\times10^5J/kg)$$
Solve for v = 360 m/s.
