Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Block and Tackle System

  1. May 30, 2006 #1
    Given a block and tackle system and a known weigt, give the magnitude of the forces at the numbered points. [see attached for figure]

    My answers:
    Point 2: 20
    Point 3: 20
    Point 4: 10
    Point 1: 40

    I arrived at the answers simply by looking at the figure and do a force balance at each tackle. I think some (if not all) are wrong because the systems doesn't provide any mechanical advantage (according to my answers). Please Help.

    Attached Files:

  2. jcsd
  3. May 30, 2006 #2

    Doc Al

    User Avatar

    Staff: Mentor

    Looks OK to me (assuming all ropes are essentially vertical). Why do you say there's no mechanical advantage? A 10 unit weight (shown) lifts a 20 unit weight (that's point 2).
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook