Heat Energy and Bullet Mass Calculation

A gun fires a lead bullet of temperature 300K into a wooden block. The bullet having melting temperature of 600 K penetrates into the block and melts down. If the total heat required for the process is 625 J, then the mass of the bullet is ___ grams. (Latent heat of fusion of lead = 2.5 × 10⁴ JKg^–1 and specific heat capacity of lead = 125 JKg^–1 K^–1)