Static equilibrium of diving board

[barz1]

Homework Statement

A uniform diving board of mass=27kg and length x=4.3m is supported by two beams. beam A at x=0m and beam B at x=1.1m. A 68kg diver stands at the other side of the board.
A. Find force on support A.
B. Find force on support B.

Homework Equations

Net force = 0
Net torque = 0
m_d=68kg -mass of diver
m_b=27kg - mass of board
l = 4.3m - length of board

The Attempt at a Solution

I am just having a lot of trouble figuring out the forces and toques for these static equilibrium problems. So I set my ForceNet = 0 = m_d*g + m_b*g - F_A - F_B. (Not sure if this is correct)
TorqueNet = m_d*g*l + m_b*g*(l/2) - F_A*(0)? - F_B*1.1
So I guess I don't understand what to use as my pivot point because this torque equation gets rid of my F_A all together.

Thanks!

 

[rock.freak667]

The Attempt at a Solution

I am just having a lot of trouble figuring out the forces and toques for these static equilibrium problems. So I set my ForceNet = 0 = m_d*g + m_b*g - F_A - F_B. (Not sure if this is correct)

Yep that is correct.

TorqueNet = m_d*g*l + m_b*g*(l/2) - F_A*(0)? - F_B*1.1
So I guess I don't understand what to use as my pivot point because this torque equation gets rid of my F_A all together.

What you did was take the sum of the torques about the point A, so this will give you F_B

Remember, the sum of the torques about any point is zero.

So if you want F_A, you can sum the torques about point B.