# Homework Help: Tension in a string at an angle

1. Feb 9, 2010

### BikeSmoth

1. The problem statement, all variables and given/known data
A wire of negligible mass is used to hang a 2.15 kg picture. The ends of the wire are attached to the top 2 corners of the picture. Each end of the wire forms an angle of 15.0 degrees from the horizontal. What is the tension in the wire?

2. Relevant equations
$$\Sigma$$F=ma

3. The attempt at a solution
This is my latest and posiibly best attmept so far, but I don't have anyone to tell me if its right or not.
$$\Sigma$$F+(-ma)=2Tsin$$\theta$$-ma=0
2Tsin15-19.737=0
T=38.1N

2. Feb 9, 2010

It's correct

3. Feb 9, 2010

### dacruick

on which wire would you like the tension for?

4. Feb 9, 2010

### rock.freak667

Yes it looks correct to me.

Though you should put ΣFy=0 when the picture is in equilibrium and then rearrange to get T.

2Tsinθ-mg=0

5. Feb 9, 2010

### BikeSmoth

there is only one wire with the picture connected at the two ends hanging down.

6. Feb 9, 2010

### BikeSmoth

well it looks like my brilliant self put 9.18 instead of 9.81 in my calculator and subsequently got the question wrong. Man I hate online homework so much!!!!!!!!!!!!!!!!!!!