# Homework Help: A question about Tensions

1. Mar 31, 2013

### kastamonu

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

Identical K,L and M bodies with a weight of P are in equilibrium . If the tension in the rope S1 is T1 and S2 is T2, then what is the ratio T1/T2? (The picture is below)

2. Relevant equations

3. The attempt at a solution

T1 equals P. But I am stuck with T2. I cannot decide whether it is 2P or 3P. Do we have to add the weight of K to T2? If we add, it will be 3P.

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Last edited by a moderator: Mar 31, 2013
2. Mar 31, 2013

### HallsofIvy

S2 is the uppermost vertical string and so must support all of the weight. Its tension will be 3P.

3. Mar 31, 2013

### kastamonu

Then the answer is 1/3.But according to my book the answer is 1/2.

4. Mar 31, 2013

### kastamonu

the pulley is attached to a rigid support.T2 has a weight of 2P

5. Mar 31, 2013

### Coelum

Let us call A the node above K and B the node above L. Let us assume that the angle between a horizontal line and the rope connecting A to B is 45 degrees (without this value you cannot compute a solution). Then you only have to write the equilibrium conditions at nodes A (first) and B (second).
The ratio is 1/2.

6. Mar 31, 2013

Many Thanks