$7\mathrm{.}4$ A rectangular steel plate hangs vertically from a hinge an

its top horizontal edge. The plate material is nild steel

thick. A jet of water $20$ dianater strikes the plate

horizontally $200$ min from the hinge vith a velocity of $6\frac{m}{s}..$

Calculate the force requiced at the lower edge of the plate

to keep the plate in a vertical position. If the velocity

of the jet is now increased to $24\frac{m}{s},$ determine what the

magnitude of the horizontal force on the lover edge must be

to limit the deflection of the plate to $45.$ Assure the

position of the nozzle and the hinge does not change

relatively to each other.