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

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 × 10^4 JKg^–1 and specific heat capacity of lead = 125 JKg^–1K^–1)

(1) 20 

(2) 15 

(3) 10 

(4) 5                   (JEE-2025)