Thermodynamics Part 5

A gun fires a lead bullet of temperature 300 K 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 =2.5×104JKg−1 and specific heat capacity of lead 125JKg−1K−1 )