Figure shows rough sketch of a selected representative critical part of a "Quick Coupler" (of an earth moving equipment) made with cast steel.  You need to perform FEA analysis to estimate critical stress levels at given operational conditions.   You can assume applied load as P = 3kN.   Your tasks: (Follow FEA reporting format where necessary)

1.  Perform an FEA analysis for portion of the Quick Coupler with suitable constraints.  (Hint: You can assume the sketch (b) represents the actual loaded component of the coupler. this critical part is taken from the circled area.  You can consider the surfaces below the centre line (CL)s to be free and the top surface of the sketch to be rigidly connected to the larger body of the coupler)

2.  Estimate the stress level at point A using your knowledge in "Stress Analysis".   Use only the given dimensions, and list clearly your assumptions and justify them.  

3.  Tabulate and compare FEA results with manually calculated values.  Explain the differences in the answers you determined from FEA and manual estimates.  Justify your comments.