1. ME 221Lecture 151 ME 221 Statics Lecture #15 Section 4.3

2. ME 221Lecture 152 Homework #5 Chapter 3 problems: –48, 51, 55, 61, 62, 65, 71, 72 & 75 –May use MathCAD, etc. to solve –Due today

3. ME 221Lecture 153 Homework #6 Chapter 4 problems: –10, 11, 18, 24, 39, 42, 43 & 47 –Must use integration methods to solve –Due Monday, October 14

4. ME 221Lecture 154 Quiz #4 Wednesday, October 9

5. ME 221Lecture 155 Last Lecture: The concepts of distributed loads, centroids and center of gravity were presented.

6. ME 221Lecture 156 Centroid of an Area Geometric center of the area –Average of the first moment over the entire area –Where:

7. ME 221Lecture 157 Centroid of an Area Is then defined as an integral over the area. Integration of areas may be accomplished by the use of either single integrals or double integrals.

8. ME 221Lecture 158 Centroid of a Volume Geometric center of the volume –Average of the first moment over entire volume –In vector notation:

9. ME 221Lecture 159 Examples