Simply supported beam — imperial units throughout

Demonstrates unit tracking across a mixed-unit calculation.

unit klf =

\frac{1000 lbf}{ft}

w

2.5 klf

L

30 ft

Maximum moment and shear

M

\frac{w \cdot L^{2}}{8}

\frac{2.5 klf \cdot {(30 ft)}^{2}}{8}

381324 J

Vmax

\frac{w \cdot L}{2}

\frac{2.5 klf \cdot 30 ft}{2}

166808 N

M

281.25 kip*ft

Vmax

37.5 kip

Required section modulus, A992 steel

Fy

50 ksi

Sreq

\frac{M}{0.9 \cdot Fy}

\frac{381324 J}{0.9 \cdot 50 ksi}

0.00122903 m^{3}

Sreq

75 {in}^{3}