Question $5$

Please show all calculations. A beam is made of four boards, nailed together. This cross$-$section will be used as a beam to carry the

concentrated load of $20KN$ and distributed load of $2K\frac{N}{m}$ along its span. Nails are uniformly spaced

along the span of the beam at $100mm$ interval. Determine $($a$)$ magnitude of the maximum horizontal

shear stress in the beam, $($b$)$ shear force in each nail, $($c$)$ magnitude of the maximum normal stress in

the beam.