In: Advanced Math
A circuit consisting of a resistor, capacitor and power supply is called an RC circuit. Physics and Kirchoff’s laws imply that if Q is the charge on the capacitor, R is the resistance and E is the power supply, then R(dQ/dt) + (1/C)Q = E. Let R = 20, C = .1 and E = 100e −.1t. If there is no charge on the capacitor at time t=0, find the charge Q at any time after that.
In an RL circuit, as described in class, R = .1, L = 1 and E = 10(1 − e −.05t ). If there is no current in the circuit at time t = 0, find the current at any time after that.
Solve the initial value problem dy/dt = 1 − 5y/(150 − 2t) , y(0) = 5. NOTE: Since we only care about what is going on up to when the tank is empty (i.e., t < 75 minutes), you can assume 150 − 2t > 0.