Assume that the circuit shown in Figure P4．70 is underdamped，and for $t<0$ ， the circuit is in DC steady－state with $v_C=V_S$ ．After the switch is thrown at $t=0$ ， the first two zero crossings of the capacitor voltage $\nu_C$ occur at $t=5 \pi / 3 \mu \mathrm{~s}$ and $t =5 \pi \mu \mathrm{~s}$ ．At $t=20 \pi / 3 \mu \mathrm{~s}$ ，the capacitor voltage $v_C$ peaks at $0.6 V_S$ ．If $C=1.6 \mu \mathrm{~F}$ ， what are the values of $R$ and $L$ ？