Question

As shown below a canterliver beam is loaded by a uniform load of 5 lbf/in and a concentrated force of 30 lbf. The beam is 15 in length. (1) What is the direction of the moment generated by the 25 lbf force against point 0? A. +y; B.-y; C. +z; D. -z (2) What is the direction of the moment generated by the 5 lbf/in uniform load against point O? A. +y; B.-y; C. +z; D.-z (3) Draw the free-body diagram of the beam. 4) Calculate all reaction forces and moments 5 bfin 25 lbf on the beam at O.

Answer 1

Given figure: @ uniformly distributed lood 5 Uoffin Concentrated force of 2 (bf. © beam length 15in WY 5 lbf in - - - - - - - - - - --VA 7 15 in 95 lbf - Direction of moment generated by a5 lbf force against point o. Maguf 2567 By Right hand thumb rufe and also by vector Cross product (M = 8 x F vector of 8 is along x axis and that of force is along Ez axis. so nesly? 8ix Fli) Mosty 15x25 (Ex-4) Maslay 375 (-3) 147.in So direction of moment Mes tot in along -y axis so option ③ is Correct ix-k=-

2 Direction of moment generated by 5 lbflin uniform load against point o. 5 lbflin 15 in. / Moment Mau - Thịt x 1 I direction inside page direction. 15.x 5X15 (R) Msut 562.5 (h) by.in so direction of moment due to 5thf/in uniform load against point oil along uz axis so answer will be correct. free body diagram of the beam. ③ Mslly hit Masur - 7.5 in H - 1585 lbf = 75 lbf. se --- - T.5in. ith -- - Usub). - - 15 in & Musus) by {fz=0 [force about z asis] hz) = 25 lbf (R2) - Reaction at point o Efya o along Zapis. (ky). 1585 Uf - 45 ut. Reba Reaction of pointo along yaxit Here at point o, Msud, & Maslly) are reactive moments of potentior

along positive so M 5 ut 15x15x5 = 562.5 lbf-in Z direction as it's reactive. Similarly (Marlbto a 15x25 = 375 lbf. in y direction as it is reactive in Cantilever beam. along positive case of