A block is attached to the ceiling by a spring that has a force constant $k=200 N/m$. A conducting rod is rigidly attached to the block. The combined mass of the block and the rod is $m =0.3 kg$. The rod can slide without friction along two vertical parallel rails, which are a distance   $L=1 m$apart. A capacitor of known capacitance $C=500 \mu F$ is attached to the rails by the wires. The entire system is placed in a uniform magnetic field $B =20 T$ directed as shown. Find the angular frequency (in rad/sec) of the vertical oscillations of the block. Neglect the self -inductance and electrical resistance of the rod and all wires