A resistor R and a capacitor C are connected in series in a circuit that contains a battery, an ammeter and switch as shown below. The capacitance is 4.81 F and the emf ? of the battery is 42 V. The resistance is not known. The time-constant of the circuit is tau (?) sec. The capacitor is initially uncharged and the switch closes at t=0.00 s. Determine the charge on the capacitor when t = 2? . Give answer in C and to two places to the right of the decimal.