For a continuous flow settling tank $3$m deep and $60$ m long, what would be the flow velocity of water for effective removal of $0\mathrm{.}025$ mm particles at $25.$ The specific gravity of the particles is $2\mathrm{.}65$ and viscosity of water may be taken as $0\mathrm{.}012/$sec$.$

$1\mathrm{.}125$ cm$/$sec

$0\mathrm{.}7$ cm$/$sec

$2\mathrm{.}60$ cm$/$sec

$0\mathrm{.}076$ cm$/$sec