CVEN1300 ENGINEERING MECHANICS FOR CIVIL ENGINEERS
(1) TIME ALLOWED – THREE (3) HOURS
(2) TOTAL NUMBER OF QUESTIONS – 6
(3) TOTAL MARKS = 100
(4) ANSWER ALL QUESTIONS
(5) QUESTIONS ARE NOT OF EQUAL VALUE.
(6) THIS PAPER MAY BE RETAINED BY CANDIDATE.
(7) CANDIDATES MAY BRING INTO THE EXAMINATION: Calculator, drawing instruments and one A4 double sided paper with any information they choose written on them. Photocopies of such sheets are an acceptable alternative. Anything else is not, including sheets with material glued or stapled to them. These sheets must be submitted with your examination paper.
(8) ALL ANSWERS MUST BE WRITTEN IN INK. EXCEPT WHERE THEY ARE EXPRESSLY REQUIRED, PENCILS MAY BE USED ONLY FOR DRAWING, SKETCHING OR GRAPHICAL WORK.
Question 1: (18 marks) The beam shown in Figure 1 carries a uniformly distributed load of 10 kN/m, plus two 100 kN concentrated loads as shown. 1) Calculate the reactions at B and E 2) Draw the shear force and bending moment diagrams, clearly indicating the magnitude and sign of all actions at A, B, C, D and E. 100 kN 10 kN/m
A
B 100 kN 5m 8m
C
D
E
6m Figure 1
4m
Question 2: (18 marks) For the frame shown in Figure 2, 1) Find the reactions at A and D. 2) Draw the axial force, shear force and bending moment diagrams for the frame, showing the magnitude of all peak values. 10 kN/m
B
C
D 5m
100 kN 50 kN A
4m Figure 2
6m
Page 2/4
PLEASE TURN OVER
Question 3: (14 marks) For the pin-joined truss shown in Figure 3, 1) Find the reactions at A and F. 2) Determine the axial force in members BC, GC, GH and CH. State if these members are in tension or compression.
A
B
C
D
E
3m 50 kN F 4m G 4m H 4m I 20 kN 4m
Figure 3
Question 4: (16 marks) For the section shown in Figure 4, 1) Find the coordinates of the centroid, xc and yc. 2) Calculate the second moment of inertia Ix´ and Iy´ at the centroid. Note: all dimensions are in mm. y
600 y´ xc
400
50
Centroid yc
x´
50
300 x
50 Figure 4 Page 3/4 PLEASE TURN OVER
Question 5: (16 marks) The coefficient of friction between the 25-kg crate and the inclined surface are 0.25 and 0.23. If the crate starts from rest and the horizontal force F=40 N, what is the magnitude of the velocity of the crate when it has moved 3 m?
F
30° Figure 5
Question 6: (18 marks) The 2-kg box A is dropped from the rest 2 m from the top of the 5-kg plate B, which is supported by the spring having a stiffness 500 / . If 0.6 between the box and the plate, determine the maximum compression imparted to the spring. Neglect the mass of the spring.
