# Name: Hour: Unit VIII: Worksheet 3. Moment of Inertia I = mr2 Point

```Name:_____________________
Hour:_____________________
Unit VIII: Worksheet 3. Moment of Inertia
I = mr2
Point mass
I = 1/3 ml
I=&frac12;mr
2
2
Rod (Axis of Rotation at end of rod)
Disc
A rod is rotating around an axis at the left side of the rod as shown
(top-down view).
1)Calculate the moment of inertia for the rod if its length doubles and
its mass is constant.
2) Calculate the moment of inertia for the rod if its length doubles and its density remains
constant.
3) How does the moment of inertia of a rod change if its mass is cut in half and its length is
tripled?
4) You thrown a 170g Frisbee whose radius is 10cm. What is the frisbee’s moment of inertia?
5) Your friend throws a 140g Frisbee whose radius is 7cm. What is this frisbee’s moment of
inertia?
6) What kind of difference would you feel when throwing each of those two Frisbees?
7) Calculate the moment of inertia for the two point masses attached to the
massless axis as shown to the right. (You are only solving using the two point
masses).
```