Question

4- For the truss shown below a-The truss shown is externally (circle correct answer) (2 point) a) determinate and unstable b) indeterminate and stable c) determinate and stable d) indeterminate and unstable Reason: (3 point) b- The truss shown is internally (circle correct answer) (2 point) a) determinate and unstable b) indeterminate and stable c) determinate and stable d) indeterminate and unstable Reason: (3 point) - Place an “O” on members with zero force on the truss (5 points) d-Solve for internal force in member BI = (5 points) CD (5 points) DH (5 points) 20 60 K ] 20 ft B |С D 25 K 4 @ 20 ft = 80 ft

Answer 1

soin) GOK ২০২ tano = 20 20 0 = 450 H J 25 x 40+30X60 luft EMA = O =) +60X20. - Eyx 80 =0 B 20 20 D - Tey 25 K Ey 42.5k Ау Ay aj statie external indeterminacy (Dee) (in ao) Dse = R-3 CR No. of external sexe this? =0 so truss is determinate of stable. Dse = 3-3 [ May No of member m - 2J +3 JNo of Joints bl internal indeterminacy (Osi) Dsi = (in ao Isi - 17- 2x10 +3 so truss is determinate (stable because it is & stable ২০k c) Gok F ZIN E A 25K 20 section - S truss by j cutting FHIL FRI le 25 O B 43.SK IFBI ২৩ K Efy=0 > FBL +42.5-20 Font = 2.5k Tensile Cutting o truss by Section ® - EMHFO => Fco X20 + 20x20 -42.5x40 00 FCD = 65 R ] Tensile. Ety = 0 -> Fro(Sino) + 42.5-20 =0 Fro S131.83K Compressive Fink Har Frisia E YE 2 FOD TARS