Find the Maximum (absolute) Vale of the Bending Moment

[Northbysouth]

Homework Statement

Draw the shear and moment diagrams for the loaded beam. Then answer the questions. The distance x is measured from point A to the right.

I have attached an image of the problem.

Homework Equations

The Attempt at a Solution

I've managed to answer everything but the maximum bending moment correctly.

What I've tried is to take a FBD of the beam from point A to somewhere in the region where the 570 lb/ft force acts. Then knowing that Ay = 1795.5 lb and that V =0 (V is the shear force) I calculated

ƩM_A=0
0 = -(570 lb/ft)(3.15 ft)(6.3 + 3.15) + M
M = 33934.95 lb/ft

But it says my answer is wrong and I'm at a loss as to what I'm doing wrong.

Help would be greatly appreciated. Thank you.

 

[Northbysouth]

I just found my mistake. It should be:

M = 570*3.15*(3.15/2 + 6.3)
M = 14139.5625 lb.ft