🔍 Key Concepts

• Mechanical advantage (MA) of tackles = how many times the effort is multiplied • Difference between a single whip, gun tackle, luff tackle, and twofold purchase in terms of number of parts of line supporting the load • How the number of supporting rope parts changes the MA when the hauling end moves vs. is fixed

💭 Think About

• For each tackle, picture or sketch the blocks and count how many parts of the line actually support the moving load block • Ask yourself: if I pull 1 foot on the hauling part, how far does the load move in each arrangement? Less load movement for the same pull distance means higher mechanical advantage • Compare which system has the fewest supporting parts of line on the moving block, since that will give the smallest mechanical advantage

✅ Before You Answer

• For each choice, carefully count the number of rope parts supporting the moving block (or load) • Confirm whether the hauling part is on the moving block or the fixed block, because that changes MA by 1 • Verify that the tackle with the fewest effective supporting parts of line provides the least mechanical advantage