2. A crane hoist is required to raise 0.10 tonnes at a speed of 0.25 m/s. The hook is mounted on a block which carries a single pulley sheave. One end of the hoisting cable is anchored on the crane trolley and the other is wound up on a winch drum 25 cm in diameter. The drum is driven by worm reduction gearing of ratio 45:1. The whole mechanism may be considered to be 60% efficient. Determine the power and speed rating of the motor and the braking torque exerted by the motor when it lowers the load at a rate of 0.3 m/s.

2. A crane hoist is required to raise 0.10 tonnes at a speed of 0.25 m/s. The hook is mounted on a block which carries a single pulley sheave. One end of the hoisting cable is anchored on the crane trolley and the other is wound up on a winch drum 25 cm in diameter. The drum is driven by worm reduction gearing of ratio 45:1. The whole mechanism may be considered to be 60% efficient. Determine the power and speed rating of the motor and the braking torque exerted by the motor when it lowers the load at a rate of 0.3 m/s.

Introductory Circuit Analysis (13th Edition)

13th Edition

ISBN:9780133923605

Author:Robert L. Boylestad

Publisher:Robert L. Boylestad

Chapter1: Introduction

Section: Chapter Questions

Problem 1P: Visit your local library (at school or home) and describe the extent to which it provides literature...

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