Physics "three strings" help?

Three strings, in the horizontal plane, meet in a knot and are pulled with three forces such that the knot is held stationary. The tension in string 1 is T1 = 3.6 N. The angle between strings 1 and 2 is q12 = 130° and the angle between strings 1 and 3 is q13 = 120° with string 3 below string 1 as shown. (THis is the link to the picture relating to the question: https://tycho2-s.phys.washington.edu/cgi...





a) Find the tension in string 2.





b) Find the tension in string 3.





c)If the sizes and directions of T2 and T3 remain the same, but T1 is increased by 3.4 N, what is the acceleration of the mass?

Physics "three strings" help?
Ok, for this problem we need to use the law of sines :





T1 / sintheta1 = T2 / sintheta2 = T3 / sintheta3





theta1 = angle between T2 and T3 = 360 - (250) = 110º





theta2 = angle between T3 and T1 = 120º





theta3 = angle between T1 and T2 = 130º





3.6 / sin110 = T2 / sin(120) = T3 / sin(130)





Using the first two :





T2 = 3.31 N





Using the other two equations :





T3 = 2.92 N





c) Here you need to use geometry to find the angles with the horizontal of T2 and T3, to decompose those forces :





T1+ 3.4 - ( T2*cos(50) + T3*cos(60)) = mass*acceleration





Hope that helps

kudzu