A man on a bosun chair

  1. A man is on a bosun chair attached to a frictionless massless pulley and is holding onto the other end of a rope. (at ground level)

    a. What is the force he must pull himself up at if he is to move at a constant speed?
    Is the set up T + T = mg?

    b. If instead the rope is held by someone else, what is the force needed to pull him up at a constant speed?

    And is this set up as T = mg?

    c. What is the force exerted by the ceiling on the system for both cases?

    This one I am lost on since I need to do a free body diagram for each case.

    I dont understand why there is such a difference, in essence.
  2. jcsd
  3. Chi Meson

    Chi Meson 1,767
    Science Advisor
    Homework Helper

    a and b, you are correct. In a, there are "two tensions" pulling up on the guy in the sling. In b, there is only one tension pulling on the guy.


    how many tensions are pulling down on the pulley?
  4. Draw a free body diagram from the pulley. That should help.
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