A rectangular gate of

dimensions $1\mathrm{.}8$ m high and

$1\mathrm{.}2$ m wide is mounted in a

vertical wall of an open

rectangular tank, as

shown. The tank is filled

with SAE $30$ oil at $15\mathrm{.}6C.$

Determine the minimum

force Q that must be

applied to the top of the

gate to keep it closed if the

gate is hinged at its bottom

edge.