Three pulling strings?

3 strings, in the horizontal plane, meet and are pulled w/3 forces so the knot is held stationary. The tension in string 1 is T1=3.1 N. The angle between strings 1 %26amp; 2 is theta12=130 degrees %26amp; the andgle between 1 %26amp; 3 is theta13=120 degrees with string 3 below string 1.





a)Find the tension in string 2.





b)Find the tension in string 3.





c) If the sixes and directions of T2 and T3 remain the same, but T1 is increased by 2 N w/ a mass of 2kg, what is the acceleration of the mass?

Three pulling strings?
In polar coordinates we have:


T1 + T2 + T3 = 0





Set T1 in the x axis then


T1 = |T1|X = 3.1N





T2 = |T2|cos(230)X + |T2|sin(230)Y





T3 = |T3|cos(120)X + |T3|sin(120)Y





Therefore





|T2|cos(230)+|T3|cos(120)+3.1 = 0


and


|T2|sin(230)+|T3|sin(120) = 0





|T2|cos(230)+|T3|cos(120)+3.1 = 0


and


|T2|sin(230)+|T3|sin(120) = 0





Solving this gives


a)





|T2| = 3.1/(cos120 - sin120*cos230/sin230)*(sin120/sin230)


|T2| = 2.85698





b)





|T3| = -3.1/(cos120 - sin120*cos230/sin230)


|T3|= 2.527143





c)





sixes? sorry I don't understand the question
Reply:These are three concurrent forces in equilibrium,use Lami's theorem,


T2/ sin 120=T1 /sin 110


T2=3.1*867/766=2.87 N





T3/ sin 130=T1 /sin 110=2.53 N


I cannot understand (c) part please state with more details