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Calculate σ_x for r_i = 1 cm

Remember elementary statics? It gives the bending stress at point O as

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Using my calculator, I get σ_x=-101.7 MPa. We'll check the MATLAB result against this value.

Calculate σ_x at point O

In your program, leave a blank line and start a new section for calculating σ_x at point O with an explanatory comment line. Then, create the parameters M, ro, and ri since these are needed to calculate σ_x.

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