---
title: "Two masses, \\( m_y = 32 \\) \\( \\text{kg} \\) and \\( m_z = 38 \\) \\( \\text{kg} \\), are connected by a rope that hangs over a pulley. The pulley is a uniform cylinder of radius \\( R = 0.311 \\) \\( \\text{m} \\) and mass \\( 3.1 \\) \\( \\text{kg} \\). Initially, \\( m_y \\) is on the ground and \\( m_z \\) rests \\( 2.5 \\) \\( \\text{m} \\) above the ground."
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url: "https://nerd-notes.com/ubq/30395/"
date_modified: "2025-03-14T05:30:48+00:00"
---

# Two masses, \( m_y = 32 \) \( \text{kg} \) and \( m_z = 38 \) \( \text{kg} \), are connected by a rope that hangs over a pulley. The pulley is a uniform cylinder of radius \( R = 0.311 \) \( \text{m} \) and mass \( 3.1 \) \( \text{kg} \). Initially, \( m_y \) is on the ground and \( m_z \) rests \( 2.5 \) \( \text{m} \) above the ground.

Two masses, \( m_y = 32 \) \( \text{kg} \) and \( m_z = 38 \) \( \text{kg} \), are connected by a rope that hangs over a pulley. The pulley is a uniform cylinder of radius \( R = 0.311 \) \( \text{m} \) and mass \( 3.1 \) \( \text{kg} \). Initially, \( m_y \) is on the ground and \( m_z \) rests \( 2.5 \) \( \text{m} \) above the ground.

**Part a)** If the system is released, use conservation of energy to determine the speed of \( m_z \) just before it strikes the ground. Assume the pulley bearing is frictionless. *(3 points)*

**Part b)** Verify your answer to part (a) by using forces, torque, and kinematics, instead. This part also serves to drive home how conservation of energy can often be used to dramatically simplify problem solving. *(3 points)*


*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/30395/*