Chapter 9.2, Problem 30SSC

To determine

Effect of thickness and heaviness on rotational properties of the plastic disc.

Answer to Problem 30SSC

Plastic disc with heavy and thick outer rim will be more stable when it flies through air.

Explanation of Solution

Introduction:

Angular momentum: Product of mass and angular velocity is equal to angular momentum

A large part of mass of Plastic disc with heavy and thick outer rim is concentrated at the rim, due to which its moment of inertia increases. Hence, when the fly is in the air, it started spinning, and angular momentum of this heavy and thick rim disc is larger in comparison to a thin and light rim disc where most of the mass is concentrated at the center. Hence,due to larger angular momentum, the disk fly with more stability.

Conclusion: Plastic disc with heavy and thick outer rim will be more stable when it flies through air.