Muet Sample

EM/OCT2009/MEC111

UNIVERSITI TEKNOLOGI MARA FINAL EXAMINATION

COURSE COURSE CODE EXAMINATION TIME

: : : :

STATICS MEC111 OCTOBER 2009 3 HOURS

INSTRUCTIONS TO CANDIDATES 1. 2. 3. This question paper consists of five (5) questions. Answer ALL questions in the Answer Booklet. Start each answer on a new page. Do not bring any material into the examination room unless permission is given by the invigilator. Please check to make sure that this examination pack consists of: i) ii) the Question Paper an Answer Booklet - provided by the Faculty

4.

DO NOT TURN THIS PAGE UNTIL YOU ARE TOLD TO DO SO
This examination paper consists of 6 printed pages
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QUESTION 1 a) Describe the meaning of force and state the general characteristic of force with an appropriate diagram. (6 marks) The 550 kg crate is suspended by the cable AB, AC, CD, CE and CF as shown in Figure Q1(b). Calculate the tension in each cable. (14 marks) z 3.0m

b)

QUESTION 2 a) Figure Q2(a) shows three forces acting on a simple horizontal supported shaft. i) ii) Replace the three forces by a single resultant force. Specify the location of the corresponding resultant force that measured from end B. (12 marks)

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3.5 m

2.5 m 2.0 m

3.0 m

300 kN 700 kN
Figure Q2(a) b)

350 kN

Figure Q2(b) shows a poie supports a 110 kg traffic light. Calculate the moment of the weight of the traffic light about the base of the pole A. (8 marks)

Figure Q2(b)

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QUESTION 3 a) Describe the meaning of simple truss. Draw an appropriate diagram. (4 marks) b) The truss supports the loads as shown in Figure Q3(b). Knowing that aII joints are pinned: i) ii) iii) iv) Draw a free body diagram of the truss as a whole, Calculate the reaction at point A and G. Identify the Zero-Force member. Determine the force in members BG and AB. State whether each member is in tension or compression. (16 marks)

p Figure Q3 (b)

5m

*\

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QUESTION 4 a) How are the radii of gyration of an area determined? Sketch the appropriate diagrams. (6 marks) Locate the centroid of the plane area shown in Figure Q4(a). All dimensions are in cm. (14 marks)

b)

Figure 0.4(a)

QUESTION 5 a) Two blocks A and B have a weight of WA = 25 N and W B N respectively as shown in Figure Q5(a). Block B is resting on the incline for which the coefficients of static and kinetic friction are 0.35 and 0.25 respectively. If the incline angle 9 = 30°, determine the smallest and the largest value of WB for which the system is in equilibrium. (9 marks)

Figure Q5(a)

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b)

The 16-N block A is attached to link AC and rests on the 24-N block B as shown in Figure Q5(b). Knowing that the coefficient of static friction is 0.20 between all surfaces of contact and neglecting the mass of the link, determine the value of 8 for which motion of block B is impending. (11 marks)

10 N

Figure Q5(b)

END OF QUESTION PAPER

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