The distance between two telephone poles is 49 m. When a 1.6 kg bird lands on the telephone wire midway between the poles, the wire sags 0.149 m. The acceleration of gravity is 9.8 m/s2 . How much tension in the wire does the bird produce? Ignore the weight of the wire. Answer in units of N

2 answers

weight = 1.6 * 9.8 = 15.68 N

T in each side of wire

do right half, left the same
1/2 weight = 7.84 N
half distance = 24.5
theta angle between vertical and wire
Tan theta = 24.5/.149
theta = 89.65155
so cos theta = .00608152
T cos Theta = half the weight
T = 7.84 N/.00608152 = 1290 N
613