Parallel Axis Theorem Video Lessons

Concept

# Problem: Calculating Moment of inertia: A 12-cm-diameter CD has a mass of 21 g. What is the CD'S moment of inertia for rotation about a perpendicular axisa) through its center and b) through the edge of the disk.

###### FREE Expert Solution

Moment of inertia about the center of a disk:

$\overline{){{\mathbf{I}}}_{\mathbf{c}\mathbf{m}}{\mathbf{=}}\frac{\mathbf{1}}{\mathbf{2}}{\mathbf{m}}{{\mathbf{r}}}^{{\mathbf{2}}}}$

Moment of inertia about a parallel axis:

Where d is the distance from the center of mass.

(a)

Icm = (1/2)mr2 = (1/2)(21 × 10-3)(0.062

###### Problem Details

Calculating Moment of inertia: A 12-cm-diameter CD has a mass of 21 g.

What is the CD'S moment of inertia for rotation about a perpendicular axis

a) through its center and

b) through the edge of the disk.