As the block does not melt completely, therefore, final temperature is zero degree Celsius.
For Ice:
Mass=428g
S.H.C./S.L.H.=?(L)
InitialTemp.=0oC
FinalTemp.=∴θR=0oC
for Metal ball:
Mass=400g
S.H.C./S.L.H.=0.6Jg−1oC−1
InitialTemp.=600oC
FinalTemp.=∴θF=(600−0)
=600oC
Heatgainedbyicetomelt=mLice
=428g×L
Heatlostbymetalball=mcθF
=400×0.6×600
=144000J.
Heatgained=Heatlost
=428g×L=144000J.
L=144000428=336.4Jg−1