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)R=Iα,a=αR(T_2-T_1)R=I\alpha,\qquad a=\alpha R
problems.proof.analysis

Unequal tensions provide the pulley torque. No slip equates tangential rim acceleration to the string acceleration, a=αRa=\alpha R.