Answer:
Ellen will maintain a tension of -513.274N
Tension in the vertical main cable of the piano is 13.274N.
Explanation:
Using Lami's theorem
T1/sinA1 = T2/sinA2
Where A1 is the total angle at Tension 1(500N) = 90+15= 105°
Where A2 is the total angle at Tension 2 = 90+25= 115°
500/sin 115 = T2/ sin105
T2 = -513.274N.
T3 ( tension in the main cable) is calculated knowing that net Tensional force is zero.
T3+ 500-513.274=0
T3= 13.274N.