A 1.0 μF capacitor is being charged by a 6.0 V battery through a 10 MΩ resistor. I need help solving these parts:

A) Determine the potential across the capacitor at time t=1.0s. Express your answer in volts.
B) Determine the potential across the capacitor at time t=5.0s. Express your answer in volts.
C) Determine the potential across the capacitor at time t=20.0s. Express your answer in volts.

3 answers

well, you know that after time t, the voltage is
VC = VS(1 - e^(-t/RC))

so plug in your numbers.
and here R =10*10^6 and C = 10^-6 just to make RC easy
A. X = t/RC = 1/(10*10^6)(10^-6) = 0.1.
Vc+Vr = 6
Vc = 6-Vr = 6-E/e^x = 6-6/e^0.1 = 0.571 volts.

Use same procedure for B and C.