The pulley system shown is at rest when the motor M starts pulling in rope so as to lift the 120lb cargo C. For the first second of operation, the motor can produce a tension in the rope of the form Fo(1 + 1/7), where Fo = 40lb. Neglect the inertia of the pulleys and of the rope. Use the impulse-momentum principle to find the value of r needed for the cargo C to travel upward with a speed of 10 ft/s after 1 s. Ans: T = 1.61 s C

The pulley system shown is at rest when the motor M starts pulling in rope so as to lift the 120lb cargo C. For the first second of operation, the motor can produce a tension in the rope of the form Fo(1 + 1/7), where Fo = 40lb. Neglect the inertia of the pulleys and of the rope. Use the impulse-momentum principle to find the value of r needed for the cargo C to travel upward with a speed of 10 ft/s after 1 s. Ans: T = 1.61 s C

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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