Bending Stress HW

$1.$ Consider a simple beam bridge, shown below. The mass of the truck $($which is $7$ m from the right edge of the beam$)$ is $\backslash (17,000\backslash$mathrm$\{$~kg$\}\backslash ),$ the mass of the bridge is $\backslash (100,000\backslash$mathrm$\{$~kg$\}\backslash ),$ and the length of the bridge is $25$ m $.$

The concrete pillars holding up the beam are $1$ m by $1$ m $,$ and $4$ m in height

a$.$ What is the area moment of inertia of the support?

b$.$ If a force of $70000$ N is applied sideways to the top of the support, what is the torque applied to the support $($which is held in place at the bottom$)?$

c$.$ What is the bending stress associated with this force?

d$.$ The maximum bending stress of the concrete is $20$ MPa $.$ Is this exceeded here?