For t = 0 in RC circuit, After t = 0+ condition, capacitor is behave as short circuit. Voltage across the it 0. At final time, Capacitor is behave as open circuit, voltage across the capacitor at final time is equal to 15 V.
Bus Type - Known Parameter - Unknown Parameter Load Bus -P, Q - V, phase angle Generator Bus - P, V (magnitude) - Q, Voltage phase angle Slack Bus Voltage - magnitude and phase angle - P, Q