a lead bullet just melt when stopped by an obstacle. assuming that 25 % of heat is absorbed by the obstacle , find the velocity of bullet if the initial temperature was 27 oc .Melting point of lead = 327 oc , specific heat of lead = 0.03 cal /gm -0c , latent heat of fusion of lead = 6 cal /gm -0c and j = 4.2 /cals