The moment of inertia of a uniform solid disc about its central axis is measured in…
PHYSICS · Multi-part · AP · Physics 1: Algebra-based · Torque and Rotational Dynamics · Torque and Rotational Dynamics
Problem
The moment of inertia of a uniform solid disc about its central axis is measured in an experiment to be 0.40kg m2. The radius of the disc is known to be 0.20m, but its mass is not directly known.
Subsequently, a small point mass of 0.50kg is firmly attached to the rim of the disc. A second measurement now gives the combined moment of inertia of the disc–mass system about the same axis as 0.42kg m2.
(i) Using only the first measurement, determine the mass of the disc.
(ii) Calculate the theoretical moment of inertia of the disc–mass system and compare it with the second experimental value. State whether the two values are in agreement within the given data.
(iii) Suggest one plausible experimental factor that could cause any mismatch between the calculated and measured moments of inertia.