Heat And Thermodynamics

A lead bullet penetrates into a solid object and melts. Assuming that 40% of its kinetic energy is used to heat it, the initial speed of bullet is :

(Given : initial temperature of the bullet = 127\(^\circ\)C, Melting point of the bullet = 327\(^\circ\)C, Latent heat of fusion of lead = 2.5 \(\times\) 10⁴ J kg^\(-\)1, Specific heat capacity of lead = 125 J/kg K)