How Do You Solve the Static Equilibrium Problem on a Pirate Ship?

[itsalwysunny]

Homework Statement

You are on a pirate ship and being forced to walk the plank. You are standing at the point marked C. The plank is nailed onto the deck at point A, and rests on the support 0.75 meters away from A. The center of mass of the uniform plank is located at point B. Your mass is 67 kg and the mass of the plank is 45 kg.

see link for a picture of the the above problem

Homework Equations

The Attempt at a Solution

I figured that the force of the nails F_n has to equal the force of the weight of the man plus the weight of the board and the sum of the forces must equal zero but ended up with the wrong solution

 

[PhanthomJay]

Homework Statement

You are on a pirate ship and being forced to walk the plank. You are standing at the point marked C. The plank is nailed onto the deck at point A, and rests on the support 0.75 meters away from A. The center of mass of the uniform plank is located at point B. Your mass is 67 kg and the mass of the plank is 45 kg.

see link for a picture of the the above problem

What's the question?

I figured that the force of the nails F_n has to equal the force of the weight of the man plus the weight of the board and the sum of the forces must equal zero but ended up with the wrong solution

When summing vertical forces, you must also include the force from the support located 0.75 m from A. You'll need to sum moments about a convenient point to satisfy sum of moments = 0, for the equilbrium condition.