(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

I am trying to learn enough physics to understand forces in climbing anchors and am stuck with an exercise problem that I am unable to understand my misconception.

Mass-less rope, no friction.

diagrams

https://docs.google.com/drawings/pub?id=1ji6WWzHGx_GwYkb6vneJJCiyjGd8fUAREIR_6HLZbAE&w=960&h=720

2. Relevant equations

The problem question is diagram D

SB is a spring balance

T1 = 98n, correct

T3 = 98n, correct

SB = 196n, wrong, ( 98n is the correct answer )

3. The attempt at a solution

Isolating each side as in diagram B

T1 = 98n = TB1 = TB2

TB1 force is to the left, TB2 force is to the left so they will not be added together

( from a experimental view I could hold the force exerted 98n )

Putting them back together again as in diagram C

T1 = 98n = T3

TC1 = T1 = 98n

TC2 = T3 = 98n

TC1 + TC2 = 196n

TC1 force is to the left, TC2 force is to the right, so they add together

( from a experimental view I would not attempt the experiment, could be painful )

The tension force in the rope has to be equal in Diagram A

T1 = T2 = T3

but T1 and T3 are downward forces that have to be transmitted somewhere and the only place is T2 so what is T2 ?

T2 = T1 + T3 = 2x98n = 196n

as T1 = T2 = T3 , ( T1 = 98n, T2 = 98n, T3 = 196n, therefore the tension will balance to 392n / 3 = 130n )

Hopefully you can see I have tried to understand but have come to the conclusion that I have a fundamental misconception as regards tension force, could it be something similar to the common mass and weight misconception. ?

1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

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# Basic Misconception tension in rope and vectors

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