Weight suspended on three strings

[gnehus]

I'm having trouble on this problem: A weight of 21 kg is suspended by means of three strings T1,T2,T3. T1 and two are connected to a ceiling and meet at their end. T3 connects at the joint section of T2 and T3. All that you are given is the angles of T1 & T2 and the weight of the object. How would one find the tensions in each string. I understand how to find tension in a one string question...but not with three strings.

http://mysite.verizon.net/nehus/phys.bmp

 

[big man]

You have three unknowns so you will need three equations to solve the problem.

You need to break up the tensions T1 and T2 into their different components (that is, horizontal and vertical).

T3 will be equal to the force due to gravity on the mass (Mg). You now need to find two other equations. They have to do with the vertical components of T1 and T2 and the horizontal components.