Question

The distance between two telephone poles is 31 m. When a 1.54kg bird lands on the telephone wire midway between the poles, the wire sags 0.165 m. The acceleration of gravity is 9.8 m/s^2. How much tension in the wire does the bird produce? Ignore the weight of the wire.

Answer 1

Tan A = Y/X = 0.165/(31/2) = 0.01065.
A = 0.61 Degrees = B = Angle the wire makes with the hor.

-T2*Cos 0.61 + T1*Cos 0.61 = 0.
T1*Cos 0.61 = T2*Cos 0.61.
T1 = T2.

T2*sin 0.61 + T1*sin 0.61 = M*g.
Replace T2 with T1:
T1*sin 0.61 + T1*sin 0.61 = 1.54*9.8
2*T1*sin 0.61 = 15.1 N.
0.02129T1 = 15.1
T1 = 709 N. = T2.

Answer 2

15