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.
m2g−T2=m2a,T1−m1g=m1am_2g-T_2=m_2a,\quad T_1-m_1g=m_1a
problems.proof.analysis

Choose downward for m2m_2 and upward for m1m_1 as positive. The inextensible string gives both masses the same acceleration magnitude.