1. The problem statement, all variables and given/known data What mass of mater would be converted to energy to provide 3200W of Power for 3 days? 2. Relevant equations P=E/t E=mc2 3. The attempt at a solution E=P*t Subbing mc2 for energy I get mc2=P*t m=P*t/c2 m=(3200W*3Days)/(9X1016m2/s2) m= 1.066X10-13kg This answer is incorrect. What am I missing?