PROBLEMS

$14\mathrm{.}1$ A beam of rectangular cross section is $125mm$ wide and $200mm$ deep. If the maximum bending moment is $28\mathrm{.}5kN*m,$ determine $($a$)$ the maximum tensile and compressive bending stress, and $($b$)$ the bending stress $25mm$ from the top of the section.

$14\mathrm{.}2$ A rectangular beam $50mm$ wide and $100mm$ deep is subjected to bending. What bending moment will cause a maximum bending stress of $137\mathrm{.}9M\frac{N}{m^2}(MPa)?$

$14\mathrm{.}3$ Determine the bending moment in a rectangular beam $3$ in$.$ wide and $6$ in$.$ deep if the maximum bending stress is $15,000$ psi.

$14\mathrm{.}4$ A rectangular tube has outside dimensions that are $2in.$ wide and $4in.$ deep and a wall thickness of $0\mathrm{.}25$ in$.$ The tube is acted on by a bending moment of $12,000$ lb$-$in$.$ Determine $($a$)$ the maximum tensile and compressive bending stress, and $($b$)$ the bending stress $0\mathrm{.}25$ in$.$ from the bottom of the tube.

$14\mathrm{.}5$ A rectangular tube has an outside width of $100mm,$ an outside depth of $150mm,$ and a wall thickness of $10mm.$ If the bending moment is $1\mathrm{.}4kN*m,$ determine $($a$)$ the maximum bending stress in the tube, and $($b$)$ the bending stress $10mm$ from the top of the tube.

$14\mathrm{.}6$ What bending moment will cause a maximum stress of $72\mathrm{.}0M\frac{N}{m^2}$MPa $)$ in the beam with the cross section shown?