A certain 4.8-volt cellular telephone battery has a capacity of 600 mAh. (One mAh equals 3.6 coulombs.) When the battery's charge is too low to run the phone any longer (assume it is zero), the battery must be recharged. (a) How much work is done by the recharger? (b) If electricity costs you 9.0 cents per kWh, how much does one recharge cost you?