Question

For each truss below determine the forces in the members and identify which are in ompression and which are in tension. In a few sentences describe which you think is a russ to use? s -A 4m 1OKN 3m m euss-B 4M toKN BM 3m 3m 3m

Answer 1

three rorces(oY member) act at Conce pt 1 At joint n acfo Fph Fac a foint and two of them are collinear then thind borce must be zero (Da and Gc are collinear FGEO At oint E fy= O, FDE Sing+ Fee STne = o D FDE -FCE =-6.25KN G1 D E 4m FDE= 6.25KNCC) Ф A - FeF FHE + FLE COSe FDE COSe -O iokH R3 am 3m FEF= 3.75+6-25x冬+6.25メ A JorntF 11.25KN(T) EMA O Rg X 12 = 10x 6 R6= SKN RA 10-S= SKN At joint FAFFEF11.25KNCT) CAF and EF are collinear) EFo A F E tane 4Sine=4, coso: ZfyO Sine+S=o 3 At A' HaQZB FADSine O Efy o, S- A FAD= SxS 6.25 KN CC) Sine MFxMO A FeccosG-FeHニ0 FBH RA= SKN 4 FBc Coso = S .c0So=S SX3 tane FDF FE G-FHc= 0 Sine FAF FEF=11.25 KNCT) FHE FBH3.75KH CT) FAD G.25KH CC) Fsc 6.25KHC FEH 3.7S KN (T At joint FHc= O : EH and HB are collinear fuczo EfxEO FHE = fBH= 3.75 KH CT FacE FoG=7sKNCC) E H FEC 6.2s KN CT) fDE 6.25N CC) FEF 11-2N CT) Aus At joint Zyzo, FBc Sine-Fee Sine O Fec FCE 6.25 KHCT) EFxo, Fc Feccose-FcE coseo Fac 2x6.25x3-7.SKN CC) colla