As we know that in order to melt the copper we need to take the temperature of copper to its melting point
So here heat required to raise the temperature of copper is given as

We know that
melting temperature of copper = 1085 degree C
Specific heat capacity of copper = 385 J/kg C
now we have



now in order to melt the copper we know the heat required is

here we know that
L = 205 kJ/kg
now from above formula


now total heat required will be


As we know that

now we have

The correct answer for the first one is A) Breaking rocks into smaller pieces. The correct answer to the second one is A) It has more energy. Hope this helps.
The core of a star must be at the temperature of 10,000,000 degrees Celsius for hydrogen fusion to begin.