A man sits in a seat that is suspended from a rope (tension & force)

AI Thread Summary
The discussion revolves around calculating the tension in a rope and the force supported by a pulley when a man sits in a suspended seat. Participants emphasize the importance of equilibrium in the system, noting that the tension in the rope should equal the combined weight of the man, the chair, and the rope itself. There is confusion about where to measure tension, with suggestions to clarify by drawing free-body diagrams for better understanding. The necessity of showing an attempt at solving the problem before receiving help is also highlighted, as per forum rules. Overall, the conversation stresses the need for a structured approach to solving physics problems.
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Homework Statement


the rope passes over a pulley suspended from the ceiling, and the man holds the other end of the rope in his hands. What is the tension in the rope and what is the force supported by the pulley.

Homework Equations


3 theories of Newton

The Attempt at a Solution


since its in equilibrium i guess that the force in the pulley is zero. the tension in the rope at the top is the weight of the person + chair and the weight of the rope.
 
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chaotiiic said:

Homework Statement


a man sits in a seat that is suspended from a rope... (tension & force)
the rope passes over a pulley suspended from the ceiling, and the man holds the other end of the rope in his hands. What is the tension in the rope and what is the force supported by the pulley.

Homework Equations


3 theories of Newton

The Attempt at a Solution


idk.
Hello chaotiiic. Welcome to PF !

Is there any more information that goes with this question? --- like weight or mass of the man and/or the seat ?

According to the rules of this Forum: https://www.physicsforums.com/showthread.php?t=414380
Homework Help: ...

NOTE: You MUST show that you have attempted to answer your question in order to receive help. You MUST make use of the homework template, which automatically appears when a new topic is created in the homework help forums. Once your question or problem has been responded to, do not go back and delete (or edit) your original post.
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On helping with questions: Any and all assistance given to homework assignments or textbook style exercises should be given only after the questioner has shown some effort in solving the problem. If no attempt is made then the questioner should be asked to provide one before any assistance is given.​
So you need to show what you know or what you're thinking about this problem before we can help.

"idk." is probably not enough.
 
welcome to pf!

hi chaotiiic! welcome to pf! :wink:
chaotiiic said:
since its in equilibrium i guess that the force in the pulley is zero. the tension in the rope at the top is the weight of the person + chair and the weight of the rope.

yes that's correct (except that we say "the force on the pulley" :wink:)

(oh, and if you're going to include the weight of the rope, then you should include the weight of the pulley also)

ok, that was the tension in the rope at the top…

now what about the tension in the other rope? :smile:
 
@sammy thanks for the welcome. there is no additional info given. its just a written response. no math.

@tiny the problem doesn't specify which part of rope where i find tension. idk if its at the top on the pulley, tied to the chair, or held by the man's hand. after skimming through my book i guess the tension at the pulley is the weight of the rope + man + chair. the tension at point tied to the chair is just the rope. the tension held by the man's hand is also just the rope. is this right?
 
chaotiiic said:
@tiny the problem doesn't specify which part of rope where i find tension.

yes it does … it asks for the tension in the rope that passes over the pulley (ie up to the pulley, over the top, and down again)
… i guess the tension at the pulley is the weight of the rope + man + chair. the tension at point tied to the chair is just the rope. the tension held by the man's hand is also just the rope.

this doesn't make any sense :redface:

tension can't be at a point, or in someone's hand

there is a rope, it has a tension

do you know what a free-body diagram is? if so, draw one for each of the bodies in the question​
 
my teacher sucks. he gives out quizes before the actual lecture. the good news is that they are take home quizzes. yes i knda know what free body diagrams are because my book showed me a couple examples but we haven't done any in class. I am just going to put the tension is the ropes weight + man + chair.
 
hi chaotiiic! :smile:

(just got up :zzz: …)
chaotiiic said:
… yes i knda know what free body diagrams are because my book showed me a couple examples but we haven't done any in class. I am just going to put the tension is the ropes weight + man + chair.

that's no way to learn :redface:

draw the fee body diagram for the man-and-seat…

draw all the external forces on that body (how many are there?) …

now add them up :smile:
 
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