A uniform thin rod of length and mass rotates about an axis through its center and…
PHYSICS · Multi-part · CBSE · Physics · System of Particles and Rotational Motion · System of Particles and Rotational Motion
Problem
A uniform thin rod of length 1.2m and mass 3.0kg rotates about an axis through its center and perpendicular to its length. Two small masses, each of mass 0.50kg, can be attached to the rod.
• Configuration 1: The small masses are fixed to the rod’s ends.
• Configuration 2: The small masses are fixed to points 0.20m from the rod’s center.
For both configurations the assembly rotates with the same angular speed of 8.0rads−1. Neglect the size of the small masses compared to the rod length.
(a) Determine the total moment of inertia about the rotation axis for each configuration.
(b) Calculate the rotational kinetic energy of each configuration.
(c) Identify which configuration has the greater rotational kinetic energy and explain, in terms of mass distribution, why this is the case even though the angular speed is the same.