A cantilever beam has the Cross-section of an isosceles triangle with a base and height equal to 1 m each. The beam is subject to 6 MN-m of bending moment. The moment of inertia of the section is \(\frac{1}{{18}}\) m4. Find the maximum bending stress in MPa.
1
\(\frac{1}{{36}}\)
2
72
3
36
4
\(\frac{1}{{72}}\)