(Solved): Problem 8: A beam has a trapezoidal cross-section with dimensions \( a=25 \mathrm{~mm} \), \( b=20 ...

Problem 8: A beam has a trapezoidal cross-section with dimensions \( a=25 \mathrm{~mm} \), \( b=20 \mathrm{~mm} \), and \( c=15 \mathrm{~mm} \). Calculate the section modulus associated with (a) the maximum stress at the top and (b) the maximum stress at the bottom.