$2\mathrm{.}1$ In order to start your design process, you need to determine what are the external support reactions $($R$1$ and R$2)$ due to the applied

loads? $(10$pt$)$

$2\mathrm{.}2$ Use the truss you designed for $1\mathrm{.}2$ or adjust the geometry of it to create a suitable truss where the maximum compression force does

not exceed $40$ kips in any element. $($Your solution can extend above or below the supports.$)$ Solve for the internal forces in your

proposed truss using either the method of joints or the graphical method. Label each member as tension or compression, together

with the value of internal axial force. Use a red pen for tension and blue pen for compression or label them with T $($tension$)$ or C

$($compression$).(35$ pts$)$

$2\mathrm{.}3$ For the element in the truss with the highest compression force of $40$ k or less, choose the lightest weight steel pipe from the attached

table which provides a safety factor against buckling of at least $3\mathrm{.}0.$ You may assume a modulus of elasticity $E_{\text{s}\text{t}\text{e}\text{e}\text{l}}=29,000$ksi and that

truss connections are all pinned at each end. $(20$ pts$)$

$2\mathrm{.}4$ For the pipe section that you have selected from the table, what is the value of axial compressive stress in the steel for the given

loading? If the steel has an allowable compressive stress of $20$ ksi $,$ is the pipe section safe from crushing? $(10$ pts $)$

$2\mathrm{.}5$ Name one thing you could change about your truss design in order to reduce the value of maximum internal compressive force for the

given loading and span. $(10$ pts $)$