- #1
khuko
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Homework Statement
Calculate the force that the man (weight 70 kg) should exert on the rope to stay in balance.
(answer = 137,2 N)
[PLAIN]http://img651.imageshack.us/img651/7682/oefkoen.png
Homework Equations
Like I see, there are two ropes who are in equilibrium. In each rope the tension is the same but different from each other.
I suppose the sum of the tensions of both ropes are equally to the weight of the person
The Attempt at a Solution
The netforce is zero cause there's no movement or acceleration
Rope 1 = the rope who holds the chair.
Rope 2 = the rope the man holds.
in positive y-direction : T(rope1)-mg/2=0 (/2 because the weight from the two ropes are from the same person)
so T(rope1)=mg/2
the other one T(rope2)=mg/2
like you see my equations doesn't match the answer. I know that the rope 2 depends on rope 1 cause they are attached to each other. But i can't write that mathematical equation.
Can you help me?
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