Q$-4/$

Surface $AB$ is a circular arc with a radius of $2$ m and a width

of $1$ m into the paper. The distance $EB$ is $4$ m $.$ The fluid above

surface $AB$ is water, and atmospheric pressure prevails on the

free surface of the water and on the bottom side of surface $AB.$

Find the magnitude and line of action of the hydrostatic force

acting on surface $AB.$