Physics
7th Edition
ISBN: 9780321733627
Author: Douglas C. Giancoli
Publisher: PEARSON
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Chapter 4, Problem 4MCQ
A bear sling, Fig. 4-40, is used in some national parks for placing backpackers' food out of the reach of bears. As the backpacker raises the pack by pulling down on the rope, the force F needed;
a. decreases as the pack rises until the rope is straight across.
b. doesn't change.
c. increases until the rope is straight.
d. increases but the rope always sags where the pack hangs.
Figure 4-40
MisConceptual Question 4
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65. A 100-kg streetlight
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Figure 4-43 Problem 65
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7) Multiple-object systems with friction: Block A of mass 5.0 kg and block X are attached to a ropewhich passes over a pulley, as shown in the figure. An 80-N force P is applied horizontally to block A,keeping it in contact with a rough vertical face. The coefficients of static and kinetic friction betweenthe wall and block A are μs = 0.40 and μk = 0.30. The pulley is light and frictionless. The mass ofblock X is adjusted until block A moves upward with an acceleration of 1.6 m/s2. What is the mass ofblock X?
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