2. The stress at a point P is given below. The direction cosines of the normal n to a plane that passes through P have the ratio nx: Hy-. nz = 3: 4: 12. Determine

(a) the traction vector T(n);

(b) the magnitude T of T<11);

(c) the normal stress cr„;

(d) the shear stress r„; and

(e) the angle between T

Hint: Use nj + nj + nj — 1.

O"

13 13 0

13 26

-13 0

-13

-39