ES 61 SECOND EXAM

July 15, 2015

Instruction: Answer the following problems neatly and box your final answers. Draw free-body diagrams.

1. The three parallel bolting forces act on the circular plate. If the forces at A has a magnitude of FA= 200Ib, determine the

magnitudes of FB and FC so that the resultant force FR of the system has a line of action that coincides with the y-axis.

Refer to Figure 1. [10 pts.]

2. Replace the two forces acting on the post in Figure 2 by a resultant force and couple moment at point O. Express the

results in Cartesian Vector form. [10 pts.]

3. Determine the distance d between A and B so that the resultant couple moment has a magnitude of MR=20 Nm. Refer

to Figure 3. [10 pts.]

4. The lever AB is welded to the bent rod BCD which is supported by bearings at E and F and by cable DG as shown in Figure

4. Knowing that the bearing at E does not exert any axial thrust, determine (a) the tension in cable DG, (b) the reactions

at E and F. [10 pts.]

5. A frame is being hoisted into an upright position by the vertical force of F=80 lb. Determine the moment of this force

about the x axis when the frame is in the position shown. [10 pts.]

Bonus: Make a Pick-up line or Knock Knock Joke about yourself. [5 pts.]

Figure 1 Figure 2

Figure 3

Figure 4 Figure 5