### Document

```READING QUIZ
The center of gravity is a point locating the resultant weight of a
system of particles.
A) True
B) False
~
The integral  x dA for a 2-D body in the x-y plane is
called the ______ .
A) first moment of area about x-axis
B) first moment of area about y-axis
C) second moment of area about x-axis
D) second moment of area about y-axis
CONCEPT QUIZ
The centroid and center of mass of a thin plate always
coincide.
A) True
B) False
CONCEPT QUIZ
To find the location of the centroid of the shaded area, it is best
to choose a ___ .
y
y = x
A) horizontal rectangular element
2
B) vertical rectangular element
C) square element
D) triangular (polar) element
4
x
ATTENTION QUIZ
To locate the center of mass of the homogeneous solid volume
shown, a disk element is used for integration. The differential
volume of the disk is ______ .
3/2
y
=
x
y
A) dv = x3 dx
B) dv = y3 dx
½
C) dv = x6 dx
x
D) dv = (/4)x6 dx
dv
ATTENTION QUIZ
A uniform semicircular rod of mass M and radius R is supported
by a hinge at its upper end and is free to swing in the vertical
plane. Which of the following is true about the force reaction
components, Ox and Oy , at O?
A) Ox = M g
B) Oy = M R
C) Oy = 0
D) Ox = 0
O

•
•
C
```