The rate capability of a lithium-ion cell is described with the Shepherd equation. Assume that the battery has a capacity of 9A h. An individual cell has an equilibrium voltage of 4.131 V and is discharged to a cutoff potential of 2 V. where Rint is the internal resistance (0.00388 ohms), Q is the nominal capacity in A h, and K is a polarization constant (0.0151 ohms). The third term approximates the kinetic polarization where the current density in the porous electrode is assumed to be inversely proportional to the amount of unused material, and the voltage losses are proportional to the current. The last term accounts for the more rapid "exponential" initial decrease in the voltage that is observed for some cells. Assume A=0.02, B=0.1. Determine, (a) How many cells are connected in series to create a 60V output. (b) The theoretical energy of the battery. (c) Compare the theoretical energy with the energy available at discharge rates of 0.1 C, 1.0 C, and 3 C