Static equilibrium - girl on diving board

AI Thread Summary
The discussion revolves around solving a static equilibrium problem involving a diving board supported at a point with a diver at one end. The user has established the equations for forces and torques, defining normal forces at both the support point and the end of the board. They have set up the equations but are struggling with multiple unknowns and seek assistance in expressing the normal forces in terms of the weights of the diver and the board. The suggestion is to use the moment equation to derive one normal force and then apply the force equation to find the other. This approach will help simplify the problem and lead to a solution.
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Homework Statement


A diving board of length L is supported at a point a distance x from the end, and a diver weighing w1 stands at the free end (Figure 1) . The diving board is of uniform cross section and weighs w2.

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(Figure 1)​

  1. Find the force at the support point.
  2. Find the force at the end that is held down.

Homework Equations



\sum\tau_{z} = 0

\sum F_{x} = 0

\sum F_{y} = 0

The Attempt at a Solution


So first I found the x & y components of the forces on the diving board. Oh, I also defined n2 as the normal force on the left end of the board, and n1 as the normal force at the support point. Up is positive and down is negative.

\sum F_{x} = 0

\sum F_{y} = 0 = n_{1} - n_{2} - w_{1} - w_{2}

Now to take the torque about an axis, since I have a lot of unknowns here. Here I've chosen the left normal force as the axis of rotation. Counter-clockwise is positive and clockwise is negative.

\sum\tau_{n_{2}} = 0 = n_{1}(L - x) - w_{2}(\frac{L}{2}) - w_{1}(L)

Now I'm stuck and can't solve the two problems. I have a lot of unknowns and no other equations in my toolbox afaik. Help please!
 
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Use the moment equation to find n2 in terms of w1 and w2. Then you can use the force equation to find n1 in terms of w1 and w2. That's all you can do with this problem.
 
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