In Exercises $35-38,$ consider a series circuit (Figure 4) consisting of a resistor of $R$ ohms, an inductor of L. henries, and a variable voltage source of $V(t)$ volts (timet in seconds). The current through the circuit $I(t)$ (in amperes) satisfies the differential equation
$$\frac{d I}{d t}+\frac{R}{L} I=\frac{1}{L} V(t)$$
Solve Eq. (9) with initial condition $I(0)=0,$ assuming that $R=100$ ohms $(\Omega), L=5$ henries $(\mathrm{H}),$ and $V(t)$ is constant with $V(t)=10$ volts $(\mathrm{V}) .$