Two control rods are attached at A to lever AB

ENGINEERING MECHANICS Assignment-1(Last Date of submission: 21-01-2014)1. Two control rods are attached at A to lever AB as shown in fig.1. Using trigonometry and knowing that the force in the left-hand rod is F1 = 30 N, determine (a) the required force F2 in the right-hand rod if the resultant R of the forces exerted by the rods on the lever is to be vertical, (b) the corresponding magnitude of R.

2. Four forces act on bolt A as shown in fig.2. Determine the resultant of the forces on the bolt.

3. Determine the resultant of the three forces shown in fig.3.

4. Boom AB is held in the position shown by three cables as shown in fig.4. Knowing that the tensions in cables AC and AD are 900N and 1200 N, respectively, determine (a) the tension in cable AE if the resultant of the tensions exerted at point A of the boom must be directed along AB, (b) the corresponding magnitude of the resultant.

5. Two cables are tied together at C and are loaded as shown in fig.5. Determine the tension (a) in cable AC, (b) in cable BC.6. Two traffic signals are temporarily suspended from a cable as shown in fig.6. Knowing that the signal at B weighs 300 N, determine the weight of the signal at C.

7. The force P is applied to a small wheel that rolls on the cable ACB as shown in fig.7. Knowing that the tension in both parts of the cable is 140 N, determine the magnitude and direction of P.

8. A system of four forces acting on a body is shown in fig. 8. Determine the resultant force and its direction.

9. A mass of 45 kg is suspended by a rope from a ceiling as shown in fig.9. The mass is pulled by a horizontal force until the rope makes an angle of 70 with the ceiling. Find the horizontal force and the tension in the rope.

10. The Bar AC, 10m long supports a load of 6000N as shown in fig.10. The cable BC is horizontal and 5m long. Determine the forces in the cable and the bar.

11. Determine the tension in the cables AB, and AC required to hold the 40KG crate shown in fig 11. Find the tension in the cable AC and BC.

12. A horizontal line PQRS is 12m long where PQ=QR=RS=4m.Forces of 1000,1500, 500 N act at P,Q,R and S respectively and action of these forces make angles of 90, 60, 45 and 30 respectively with PS as shown in fig.12. Find the magnitude, direction and position of the resultant force.

13. A coplanar parallel force system consisting of three forces acts on a rigid bar AB as shown in fig 13.a)Determine the simplest equivalent action for the force system.(take moment about C).b) If an additional force of 10 KN acts along the bar A to B , what would be simplest equivalent action?

14. Reduce the given system of forces acting on the beam AB in fig 14 to an equivalent force-couple system at A and an equivalent force-couple system at B.

15. Find the magnitude of 2 forces such that if they act at right angles, their resultant is 10.But if they act at 60, their resultant is 13.

16. Determine the magnitude and line of action of the resultant of forces shown in fig.16.17. Two rollers each of weight 50N and of radius 10cm rest in a horizontal channel of width 35cm as shown in fig.17. Find the reaction on the point of contacts A, B, and C.

18. a) Using the method of joints, determine all the member forces in fig.18 b) Using the method of sections determine the force in the member(s) shown in bold in fig.1819. For the plane area shown in fig.19, determine (a) the first moments with respect to the x and y axes, (b) the location of the centroid.

20. Determine the moments of inertia Ix and Iy of the shaded area with respect to centroidal axes, X-axis, Y-axis and a side AB (if mentioned) for the plane area shown in fig.20.

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