Question

A bird sits on a stretched telegraph wire.additional tension produced on the wire is

Answer 1

A bird of mass m sits on a tightly stretched telegraph wire.

The additional tension produced by the bird in the wire is produced in the wire could be more than mg. 2 (T / 2) cos  = mg or T = mg /cos . 2 {(T + Ta)/2} cos  = mg or Ta = (mg /cos - T.........(1).

Now  is very large ie closer to 90 deg than to 0 deg and hence  cos would be very small. In any case it is less than 1.

Thus from eqn (1) it can be seen that T < mg /cos  since the additional tension cannot be -ve. but we can't definitely say that Ta > mg