# moment and force calculation for cantilever beam

**1. The problem statement, all variables and given/known data**

A cantilever beam (prismatic, rectangular cross section) is loaded at the tip by a force

P and at half its length L by a moment M.

a. Calculate the reaction force and moment.

b. Draw the shear force and bending moment diagrams

**2. Relevant equations**

∑F=0; ∑M=0

**3. The attempt at a solution**

a) The reaction force should be -P, so that the total force is zero. But I am not sure if it works the same for the moment, because I think the moment should always be calculated around the same point? Or should the reaction moment just be -M?

b) The shear force I calculated by looking at just a part of the beam, from somewhere in the middle completely to the right. Since it’s total force should be zero, I think the shear force would be -P (positive shear is defined as if it would rotate the piece clockwise)

But for the bending moment diagram, I am at a complete loss. I know it should be zero at the right end, but I don’t know what I would get at the left and how the moment at the middle is reflected in the diagram.

I hope I made my thoughts clear, any help would be greatly appreciated.

**1. The problem statement, all variables and given/known data**

**2. Relevant equations**

**3. The attempt at a solution**

http://ift.tt/1gkS58g

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