Question

Please answer both questions 3 & 4

-1 in. (3) Using Theorems of Pappus and Guldinus, find the area and volume of the object resulted by the revolution of the shown triangle about Z. 1 in. 2.5 in. -3.5 in. 3 ft Q4) In the truss shown, without calculating the reactions, find the zero members (by visual inspection), and find the force in member DA. -2 ft 2 ft 300 lb

Answer 1

Solution : 치 z 2 € 2.5.!! 2013 - 2/3" 3.5" Based on pappus and Guldinus theorems A = 2trch 21 YL-0 where re distance of centeroid geometry curve << length of wore

By formula of centroid of composite wove. Eda La Ela - ماك Sum of segment lengths :. NcL=Exala :. A = 271 ExaLa (2) 6. 52/2 2- T'12" + 11" √2 3 + 3'' 3.5-1 سيا + ke 3" line La χα Xala. 11 J2" 3" 4.243 2 11 I' 3.5" 3.5 3 11 I" 3' 3 EXala = 10.743 By eq" @ A - 21 X 10.743 6+5 in 2

Volume According to Pappus and Guldinus v = 2 TICA n A = LXIX 2.5 -0.5 in? 2h13 2Xh-2XL 3 3. V = 27 YA = 271 / 2.5" +2 ve 9.948 in 3

0.4 Solution :- CB joint At C ;- H CA co At state equilibrium Sv=0 CA coso, = 0 CA = 0 Zero force member joint At D :- DC Y DA 3 4 300 lb

EH = 0 Ev=0 DA UDC COS 0-0 DC sino = 300 DA + 500 x į co = 300 DCX DC =500 lb (1) DA - 400 lb (6)