Finding a max load from the yield stress

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To determine the maximum load a bar can withstand, the yield stress and dimensions of the bar must be considered. The bar is 500mm long, 10mm wide, and 3mm deep, with a maximum yield stress of 150 MPa. The bending moment was calculated to be 3.75 at 250mm, leading to an equation involving stress and moment. However, the calculated load of 9N does not align with the applied load of 30N, indicating a potential miscalculation. Clarification on the bar's support, which is simply at both ends, is crucial for accurate calculations.
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1. Homework Statement I have a bar, 500mm long (0.05m) 10mm wide (0.01m) and 3mm deep (0.003 m)The bat has a load applied in the centre of 30nI know the maximum yield stress is 150 mpa 150x10^6How do I calculate the maximum load the bar can take?2. Homework Equations I used stress = m y / I3. The Attempt at a Solution I calculated the bending moment to be 3.75 at 250mm (.25m) using a shear bending diagram,*I then reversed the equation above to get:150x10^6 = 0.0015m/2.25x10^-11Which gives m as : (150x10^6 x 2.25x10^-11) / 0.0015M = 2.25I know the bending moment is at .25 mSo divide 2.25 / .25I get 9The answer can't be 9n as the question uses 30nCan someone please show me how to solve this?.Thanks in advance x*
 
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You missed the most important point. How is the bar supported?
 
Sorry, the bar is simply supported at either end
 
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