To calculate the percentage of the original charge left on the capacitor after 1.6 seconds of discharging in a series circuit with a capacitor and a resistor, you can use the formula for the charge on a capacitor discharging through a resistor:
1. Calculate the time constant (τ) of the circuit using the formula: τ = R * C, where R is the resistance (2.0x10^5 ohms) and C is the capacitance (7.7x10^-6 F).
2. After finding τ, determine the charge remaining on the capacitor after 1.6 seconds using the formula: Q(t) = Q(0) * e^(-t/τ), where Q(0) is the initial charge on the capacitor.
3. Calculate the percentage of the original charge remaining by dividing the charge at 1.6 seconds by the initial charge and multiplying by 100.
By following these steps and plugging in the given values, you can find the percentage of the original charge left on the capacitor after 1.6 seconds of discharging in the series circuit.