Question

P.4. (10 extra credit points) If F1 = [55 k] N, F2 = [120 k] N, and F3 = [80] N, determine the resultant couple moment. Where does it act on the structure? -F. = [-150 k] N 0.3 m 30° 0.3 m 0.2 m F. = [150 k) N P10.2 m-F, 0.2 ml

Answer 1

fi = [55K)N f = [lok]n 81 282 283 29 = 0.2 -0,= dy=d3:0 44= 0.3 - 30° di ru caso f35 [so il n fu = [150kn Couples Mis fixe = F xd 55 X 0.2 clockwise direction around 4-axis. - 11 Nim - + (0-2 ) x (55K) = [-11 j] Nom ly M₂ = x slove ) x ( loole) = [24 i) Nim

M3 = [-16*] wm. M4 = 54. cos co x 74 ir distance blew (fy + -fy) = (0-3). (isole) * Cos 30 = [38.99 ;] nom Note: you unit vector l arrest on vector) can identify By inspection, between couple forces. couple [rl= distance between forces. Net couple moment, M = Mix Mae Mat My ] nom = [62.979 - 11ŷ - 16 e M = 65.9 nm

lesultant couple moment, teo 1. IMA 65.9 Nom e M= 62.971- 11 î - 16ľ (room) * Moment of a couple is a free vector It and can be moved have the same anywhere on the body external effect on the body. * It can act on the structore. on Any where