Question Detail

PHY 101 Mechanical Equilibrium and Rotational Dynamics Objective Question
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Question

Six coins, each of mass 20 g, are glued 10 cm apart on a rod of negligible mass. The rod rotates about an axis located at the 25 cm mark. To calculate the moment of inertia of this system, what principle must be applied?
Options
A The principle of moments
B The sum of the masses of the coins
C The sum of m r² for each coin, where r is the distance from the axis
Correct Answer
D The product of total mass and the square of the average distance
Correct Answer

Option C is the correct answer.

Detailed Explanation

For a system of discrete particles, the moment of inertia is defined as the sum of the products of each particle's mass and the square of its perpendicular distance from the axis of rotation, I = Σ m r². Therefore, to find the total I, one must calculate and sum m r² for each coin based on its individual distance from the axis.

Hint

Recall the definition of moment of inertia for a system of particles. Distances must be measured from the rotation axis.

Question Info

Course: PHY 101
Topic: Mechanical Equilibrium and Rotational Dynamics
Type: Objective
Difficulty: Not specified
Question 584 of 1250
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