$10\mathrm{.}10\mathrm{.}5$ A square ventilat$$ng duct measures $0\mathrm{.}3$m on each side. A Helmholtz resonator band filter is constructed hole of $0\mathrm{.}08$m radius $1$n one wall of the duct leading into a surrounding closed chamber by drilling of volume V$.($a$)$ What volume is required to filter sounds most effectively at $30$Hz$?($b$)$ What will be the power transmission coefficient of the filter at $60$Hz$?$