1. The problem statement, all variables and given/known data A step voltage of 120v is applied to a series CR circuit. C = (4x10^(-6))F R = (20x10^(3))Ω When the capacitor is fully charged the supply voltage is removed. Using KVL and Laplace transforms obtain an equation for the transient circuit current, given when t = 0, the voltage across the capacitor is at its steady state value of 120v. 2. Relevant equations 3. The attempt at a solution V = v_r + v_c 0 = Rdq/dt + q/c Laplace Transform 10: 0 = R(sq(s) - q_0) + (q(s))/c q_0 = VC = 120 x (4x10^-6) = (4.8x10^(-4)) I'm not sure about this part, I think q_0 should be this. 0 = (20x10^3) (sq(s) - (4.8x10^(-4)) + (q(s)) / (4x10^(-6)) Divide through by R = (20x10^3): 0 = sq(s) - (4.8x10^(-4)) + (q(s)) / ((4x10^(-6)) (20x10^3)) Rearranging this gave: q(s) = (4.8x10^(-4)) / (s+(25/2)) = (4.8x10^(-4)) x (1/(s + (25/2))) Laplace Transform 2: q = (4.8x10^(-4)) e^(-25t/2) i = dq/dt = d/dt ((4.8x10^(-4)) e^(-25t/2)) i = -(3/500) e^(-25t/2) A Does this seem right? I have a negative answer for current, and it is the same as the transient I found in an earlier question where I had to find the transient current when the voltage was applied, but this time negative. Any help on where I've gone wrong is appreciated! If possible could you use the differential equations like I have. Thanks!