Mechanical Engineering Principles

100 MECHANICAL ENGINEERING PRINCIPLES

3. Figure 7.35 [18636 mm^4 ]

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Figure 7.35

4. Figure 7.36 [10443 mm^4 ]

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Figure 7.36

5. Figure 7.37 [43909 mm^4 ]

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Figure 7.37

6. Figure 7.38 [8922 mm^4 ]

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Figure 7.38

7. Figure 7.39 [2342 mm^4 ]

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Figure 7.39

8. Figure 7.40 [24683 mm^4 ]

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Figure 7.40

Exercise 39 Short answer questions on

first and second moment

of areas

1. Define a centroid


2. Define the first moment of area


3. Define second moment of area


4. Define radius of gyration


5. State the parallel axis theorem


6. State the perpendicular axis theorem

Exercise 40 Multiple-choice questions on

first and second moment of

areas (Answers on page 284)

1. The centroid of the area bounded by the
   curvey= 3 x,thex-axis and ordinates
   x=0andx=3, lies at:

(a) (3, 2) (b) (2, 6)

(c) (2, 3) (d) (6, 2)

2. The second moment of area about
   axis GG of the rectangle shown in
   Figure 7.41 is: