Step-by-step explanation:
It is known that heat of fusion of copper is equal to 207 kJ/kg. Also, it is known that relation between heat energy and specific heat is as follows.
Q =

where, Q = heat energy
m = mass
= heat of fusion
Hence, putting the given values into the above formula to calculate heat energy as follows.
Q =

=

= 7058.7 kJ
Thus, we can conclude that 7058.7 kJ heat is added to melt the copper.