Name
Date
Pd
UNIT V: Worksheet 3
1. A rod with length L and mass m is rotating around an axis at the left side of the rod as shown
above (top-down view). The rod has a moment of inertia I.
a. Determine the moment of inertia for the rod if its length doubles and its mass is constant.
b. Determine the moment of inertia for the rod if its length doubles and its density remains constant.
c. How does the moment of inertia of the rod change if its mass is cut in half and its length is tripled?
2.
a. You thrown a 170g Frisbee whose radius is 10 cm. What is the Frisbee’s moment of inertia?
b. Your friend throws a 140g Frisbee whose radius is 7cm. What is this Frisbee’s moment of inertia?
c. How does the experience of throwing the two Frisbees differ from one another?
3. Calculate the moment of inertia for the two point masses attached to the massless axis as
shown below. (You are only solving using the two point masses).
A
B
C
4. Three massive spheres are connected to a rod of very small mass. Consider the moment of
inertia of the system, first when it is rotated about sphere A, and then when rotated around
sphere B. Are the moments of inertia the same or different? Defend your answer.
5. A solid cylinder and a hollow cylinder are placed at the top of a ramp as shown.
Which one reaches the bottom first?
a. Solve with 𝜏 = 𝐼𝛼.
b. Solve with conservation of energy.