Bennett Mechanical Comprehension Practice Test 2025 - Free Practice Questions and Review Guide

Increasing the radius of a flywheel significantly affects its momentum. As the radius increases, the mass distribution of the flywheel extends further from the axis of rotation. This change results in a greater moment of inertia, which is a measure of an object's resistance to changes in its rotational motion. The relationship between rotational momentum (or angular momentum) and the moment of inertia is directly proportional when considering a constant angular velocity. Therefore, if the flywheel is spinning at the same speed, the increase in radius, and consequently the increase in moment of inertia, leads to greater momentum.

This concept aligns with the principle that momentum depends on both the mass and radius of the rotating body. By increasing the radius while maintaining the same angular velocity, you effectively increase the linear velocity of the edge of the flywheel, contributing to a greater total momentum.