Keeping in mind that the conversion between calories and Joules is
[tex]1 cal = 4.186 J[/tex]
we can write the conversion factor using the kilocalories:
[tex]1 kcal = 4186 J[/tex]
The energy released in our problem is
[tex]E=3.3 \cdot 10^{10} J[/tex]
so we can set a simple proportion to find its equivalent in kcal:
[tex]1 kcal: 4186 J = x: 3.3 \cdot 10^{10} J[/tex]
from which we find:
[tex]x= \frac{3.3 \cdot 10^{10} J \cdot 1 kcal}{4186 J} =7.88 \cdot 10^6 kcal[/tex]
