Problem 4.109

In a circuit shown in Fig. 4.29 the battery emf is equal to $\mathscr{E}=2.0 \mathrm{~V},$ its inter-nal resistance is $r=9.0 \Omega$, the capacitance of the capacitor is $C=10 \mu \mathrm{F},$ the coil inductance is $L=100 \mathrm{mH},$ and the resistance is $R=1.0 \Omega$. At a certain moment the switch $S w$ was disconnected. Find the energy of oscillations in the circuit (a) immediately after the switch was disconnected; (b) $t=0.30$ s after the switch was disconnected.