As a designer, you are required to develop a new, closed, sealed thermal energy storage cell that has a maximum reversible work output of 500 Btu. The ground state total energy, total entropy, and temperature are 5.00 Btu, 0.11690 Btu/R, and 50.0°F, respectively. If the total entropy of the cell must be ten times its ground state value, what should the total energy of the cell be?