Physic Labs

Problem 1

Two small masses m1m_1 and m2m_2 are joined by a light inextensible string over a fixed pulley of radius RR and moment of inertia II with a frictionless axle; m2>m1m_2>m_1. The string does not slip, both segments are vertical, and the string's mass is negligible. Release from rest and take g=9.8 m/s2g=9.8\,\mathrm{m/s^2}. (a) Find the acceleration and pulley angular acceleration. (b) Find the tension in each segment. (c) Find the acceleration for a massless pulley and explain how it compares with the inertial pulley.
T2−T1=IR2aT_2-T_1=\frac{I}{R^2}a
problems.proof.analysis

Insert the constraint into the torque equation and divide by RR. The quantity I/R2I/R^2 has mass units and acts as rotational inertia referred to translation.