2. A load of mass 230 kg is lifted by means of a rope which is wound several times round a drum and which then supports a balance mass of 140 kg As the load rises, the balance mass falls. The drum has a diameter of 1.2 m and a radius of gyration of 530 mm and its mass is 70 kg The frictional resistance to the movement of the load is 110 N. and that to the movement of the balance mass 90 N. The frictional torque on the drum shaft is 80 N-m. Find the torque required on the drum, and also the power required, at the instant when the load has an upward velocity of 2.5 m/s and an upward acceleration of 1.2 m/s. [Ans. 9162 N-m ; 4.32 kW]

2. A load of mass 230 kg is lifted by means of a rope which is wound several times round a drum and which then supports a balance mass of 140 kg As the load rises, the balance mass falls. The drum has a diameter of 1.2 m and a radius of gyration of 530 mm and its mass is 70 kg The frictional resistance to the movement of the load is 110 N. and that to the movement of the balance mass 90 N. The frictional torque on the drum shaft is 80 N-m. Find the torque required on the drum, and also the power required, at the instant when the load has an upward velocity of 2.5 m/s and an upward acceleration of 1.2 m/s. [Ans. 9162 N-m ; 4.32 kW]

International Edition---engineering Mechanics: Statics, 4th Edition

4th Edition

ISBN:9781305501607

Author:Andrew Pytel And Jaan Kiusalaas

Publisher:Andrew Pytel And Jaan Kiusalaas

Chapter7: Dry Friction

Section: Chapter Questions

Problem 7.48P: Find the smallest distance d for which the hook will remain at rest when acted on by the force P....

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A load of mass 230 kg is lifted by means of a rope which is wound several times round a drum and which then supports a balance mass of 140 kg. As the load rises, the balance mass falls. The drum has a diameter of 1.2 m and a radius of gyration of 530 mm and its mass is 70 kg. The frictional resistance to the movement of the load is 110 N. and that to the movement of the balance mass 90 N. The frictional torque on the drum shaft is 80 N-m. 2. Find the torque required on the drum, and also the power required, at the instant when the load has an upward velocity of 2.5 m/s and an upward acceleration of 1.2 m/s?. [Ans. 916.2 N-m ; 4.32 kW]
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