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Force of Tension 
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#1
Sep609, 09:31 AM

P: 166

1. The problem statement, all variables and given/known data
Tarzan plans to cross a gorge by swinging in an arc from a hanging vine. If his arms are capable of exerting a force of 1400 N on the rope, what is the maximum speed he can tolerate at the lowest point of his swing? His mass is 80 kg and the vine is 4.8 m long? 2. Relevant equations net force = ma 3. The attempt at a solution I'm not sure how to deal with the force of tension in this problem net force radial direction = m a radial direction = Fr = Ft + Farm  Fg sense I don't know what the force of tension is in this problem I got down to this v = ((.06 kg^1 m)Ft  37 s^2 m^2)^(2^1) is the force of tension equal to what? 


#2
Sep609, 09:37 AM

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How does Farm relate to Ft? 


#3
Sep609, 09:45 AM

P: 166

oh F arm is equal to Ft ???
what about the force of gravity does that increase the force of tension sense his mass is pulling him downwards and his force of his arm is pulling him upwards? confused on which force act upwards and which act downwards tension pulls up force exerted by arm is up gravity is down radial force is upwards does Ft = Farm Fg doesn't have any thing to do with tension in this case? 


#4
Sep609, 09:49 AM

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Force of Tension
Answer my question: What forces act on the man? (Hint: Only two forces act on him.) 


#5
Sep609, 10:01 AM

P: 166

gravity and tension how
but home come gravity dosen't also pull the rope down creating tension and what about centripetal force? 


#6
Sep609, 10:07 AM

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#7
Sep609, 10:12 AM

P: 166

so the force of tension is just equal to the tension he exerts on his arm what about the force of gravity acting on the man pulling the man down and as a result pulling the rope down even more
the force of tension in the rope f arm points upwards force of gravity pulls the man downards creating more tension in the rope so does the force of tension in the rope equal the force exerted by arm  the force of gravity acting on the man 


#8
Sep609, 10:20 AM

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No matter what else happens, the man and rope exert equal forces on each other. That's Newton's 3rd law. 


#9
Sep609, 10:37 AM

P: 166

so i got 9.8 s^1 m



#10
Sep609, 10:43 AM

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#11
Sep609, 10:50 AM

P: 166

net force = m a = Ft  Fg
net force = m a = 1400 N  (80 kg)(9.8 kg^1 N) net force = m a = 1400 N  784 N net force = m a = 616 N r^1 m v^2 = 616 N v^2 = m^1 r 616 N v = (m^1 r 616 N)^(2^1) v = ( (80 kg) 4.8 m (616 N) )^(2^1) v = 6.1 s^1 m so on free body diagrams we do not lable the centripetal force because it's not a seperate force but just the name of the net froce? 


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