# Center of Mass and Moment of Inertia

1. Mar 24, 2008

### sealedhuman77

1. The problem statement, all variables and given/known data

Find the center of mass of the collection of mass points in Figure P.12 and then find the moment of inertia of the system about an axis through the center of mass and parallel to the y-axis.

2. Relevant equations

Center of Mass
Moment of Inertia

3. The attempt at a solution

M1 = 1kg, r1 = (1i + 0j) m
M2 = 2kg, r2 = (4i + 0j) m
M3 = 3kg, r3 = (6i + 0j) m
Mass total = 6kg

X of CM = 1/6 (0 + 8 + 18) = 13/3 m
Y of CM = 1/6 (0 + 0 + 0) = 0 m

I = mR$$^{2}$$
I = 6 (4.333)$$^{2}$$
I = 112.6667 kgm$$^{2}$$

The answer was wrong. Thanks for the help

#### Attached Files:

• ###### p10-12.gif
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2. Mar 24, 2008

### sealedhuman77

moving it up

3. Mar 25, 2008

### sealedhuman77

moving it up again

4. Mar 25, 2008

### nickclarson

I wouldn't keep bumping this thread until your attachment has been approved. ;)