Question 2093 Deck General

70% to pass

You are using tackle number 2 as shown in illustration D029DG below to lift a weight of 100 lbs. If you include 10 percent of the weight for each sheave for friction, what is the pull on the hauling part required to lift the weight?

Diagram for USCG Deck General: You are using tackle number 2 as shown in illustration D029DG below to lift a...
A 50 lbs.
B 55 lbs.
C 60 lbs.
D 110 lbs.
AI Explanation

The correct answer is C) 60 lbs. The reasoning is as follows: For a tackle system with 2 sheaves, the mechanical advantage is 2. This means that the load weight of 100 lbs is distributed across 2 parts of the line. However, to account for the 10% friction loss per sheave, an additional 20% of the load weight must be added to the hauling part pull. Therefore, the required pull on the hauling part is 100 lbs / 2 + (100 lbs * 0.2) = 60 lbs. The other options are incorrect because they do not properly account for the 10% friction loss per sheave in the tackle system.

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