Question

Determine the force in each member of the truss shown by the method of joints.

Answer 1

find reaction forces Du T => EV=0 Sum of vertical forcey = 0 十分 = Dy= 25k (1) Dy = = 10+ 10+5 E toft y Sk) С El=0 An LOK JB flok k laft * laft ㅕ Sum of horizontal forces = 0 7 Duttu=0 EMA =0 moment equilibrium about point & ² Du (10) & 10 (12) + 10 (24) = 0 =y/on=36k (4) you - 120 - 240 - Du=-36k Ds 10 D ✓ 10+2y = 26 (A= 36k (7) Method of joint a 10 A 94 24 joint equllibnium @ D COCOS EH= foy fto Covo = 36 tot (3) sinos 5 13 = 36 DR +869 foo=39k (Tensile) EAR & LED sino = 25 - SAD = 25 – 39 13 PAD () AD=25-15 Ino= 10k / tonsile) hu

At joint & = feca 13 10* 15) EVSO FEC Sno=10 stec c=26k Tension foc = - 26 coso =0 Y lok EHO foc + fee = fire FBC = -24k NOTE If BC= 24k ( comprension) [ Negative sign indicates comprenove force 35 At joint EVO LAE Sino & LAD LAS я FAG 5- 10 LAE = 13k (comprenion) An AB ) 15k EH=0 LAB ME = -13k = FAR + 36 + (-13 & coro) - o => =-36 + (13* 1 ) ) lan= - 244 FAR = 24k (comprension) ) ) LAB BL=24k (comp.) & BE = 10k (Tension) stoe @ for Alge Pas fiok ANSWERS BC — nature fore(K) member AB 24k - Compression 24k - y compresting CE - 264 - Tension ED 7 y Tension. AD – 7 y Tennig y Comprung ok y Tension BEY 39k lok 13k AE