Ch.6 Properties of Sections

Question 1

Most section properties are aligned with the axes of the ___

Answer 1

cross-section

Question 2

What are the units of inertia?

Answer 2

(unit of length)^4

Question 3

What is the name for the center of gravity of an object of uniform density?

Answer 3

Centroid

Question 4

What is a centroid?

Answer 4

Center of gravity of an object of uniform density

Question 5

What is the equation for a centroid?

Answer 5

where dx and dy are the distance along the matching axis of the centroid from the chosen reference origin of on the object

Question 6

Find the centroid of this object from its component parts

Answer 6

Question 7

What is a mathematical expression that describes the relative location of material in a cross section?

Answer 7

Moment of Inertia

Question 8

What is a moment of inertia?

Answer 8

Relative location of material in a cross-section. It resists bending stress and deflection

Question 9

What is another name for moment of inertia?

Answer 9

Second moment

Question 10

What is moment of inertia a measure of?

Answer 10

Cross-sectional stiffness

Question 11

How would one find the Moment of Inertia of Hollow Shapes?

Answer 11

If the centroids of two shapes coincide, you may subtract the moment of inertia of the void from the moment of inertia of the overall body. THIS IS CALLED THE NEGATIVE AREA METHOD