Figure P$10\mathrm{.}4.$

$10\mathrm{.}11.$ A cylindrical circular rod in the form of a quarter$-$ring of radius $R$ is fixed

at one end $($Fig$.$ P$10\mathrm{.}11).$ At the free end, a concentrated force $P$ is applied

in a diametral plane perpendicular to the plane of the ring. What is the

deflection of the free end? Use the unit load method. $[$Hint: At any section,

$M_0=$PRsin$$ and $[$:$T_{}=PR(1-cos).$