At a point in a stressed body, the Cartesian components of stress are

a$,=40$MPa, $=60$ MPa,a$,=40$ MPa, Txy $=80$ MPa, t$=50$ MPa, t$.,$

$60$ MPa,

Determine $($a$)$ the normal and shear stresses on a plane whose outer

normal has the direction cosines a$,,=4/9,$a$.,=4/9,$a$3,7/9$ and

the angle between the resultant stress $$ and the outer to the plane.