Final S1 memb123

COLLEGE OF ENGINEERING

PUTRAJAYA CAMPUS

FINAL EXAMINATION

SEMESTER 1 2013 / 2014

PROGRAMME : BME/BEPE/BEEE (Honours)

SUBJECT CODE : MEMB123 / MEMB214

SUBJECT : Mechanics I: Statics

DATE : September 2013

TIME : 2.5 hours

INSTRUCTIONS TO CANDIDATES:

1. This paper contains SIX (6) questions in EIGHT (8) pages.

2. Answer ALL questions.

3. Write ALL answers in the answer booklet provided.

4. Write answer to each question on a new page.

THIS QUESTION PAPER CONSISTS OF (8) PRINTED PAGES INCLUDING

THIS COVER PAGE.

Page 1 of 8

MEMB123/MEMB214, Semester 1 2013/2014

Page 2 of 8

QUESTION 1 [16 MARKS]

Figure 1 shows a lever ABC exerting a 120 N normal force on the smooth surface at

A. The unstretched length of the spring CD is 350 mm.

a) Draw the free body diagram of the lever ABC and explain the significance of

each force acting on the diagram. [5 marks]

b) Determine the value of the spring constant k and the reactions at the pin

support B. [11 marks]

Figure 1


Page 3 of 8


Ocean Liner A and Ocean Liner B are brought to their respective piers using

tugboats as shown in Figure 2. Ocean Liner A is pushed by four boats, each exerting

a 5 kN force in the direction shown. Ocean Liner B is pushed by a single boat

exerting 13 kN force in the direction shown.

(a) Draw the free body diagram of the Ocean Liner A and Ocean Liner B.

[8 marks]

(b) Do these boats produce the same effect on their respective ocean liners?

Justify your answer. [10 marks]

Figure 2


Page 4 of 8


The truss shown in Figure 3 serves to support the deck of a bridge.

a) Draw the free-body diagram of the truss and determine the support reaction at

the rocker G. [6 marks]

b) Identify all zero force members in the truss. [2 marks]

c) Determine the internal force in members DE and JI and state if these members

are in tension or compression. [9 marks]

Figure 3


Page 5 of 8


The beam shown in Figure 4 is supported by a pin at A and cable BCD,

(a) Draw the free body diagram of the beam and determine the support reaction at

support A. [7 marks]

(b) Determine the normal force, shear force, and moment at points E and F in the

beam. Show these internal forces using a free body diagram. [11 marks]

Figure 4


Page 6 of 8


The block brake in Figure 5 is used to stop the 25 kg drum from rotating by applying

a force P. The coefficient of static and kinetic friction between drum and brake

mechanism is s = 0.4 and k = 0.35, respectively. The weight and thickness of the

brake is negligible.

a) Draw the free body diagram of the brake and the drum. [4 marks]

b) If a force P = 150 N is applied to the brake, show that this force is not

sufficient to prevent the drum from rotating. [8 marks]

c) Determine the support reactions at pin O. [4 marks]

Figure 5


Page 7 of 8


For the block shown in Figure 6,

a) Locate the centroid x and y of the shaded area. [7 marks]

b) Determine the moments of inertia Ix and Iy of the shaded area about its

centroidal xo-axis and yo-axis [8 marks]

Figure 6

--- END OF QUESTION PAPER---

x

xo

yo y


Page 8 of 8

Appendix

Table of Moment of Inertia

Documents

Final S1 memb123