posted by Sean on .
The distance between two telephone poles is 50.0 m.
When a 1.00-kg bird lands on the telephone wire midway between the poles, the wire sags 0.200 m.
Draw a free-body diagram of the bird. How much tension does the bird produce in the wire? Ignore the weight of the wire.
What do I do now?
Look at the triangle formed with the wire and the horizontal, and the bird vertical.
At the bird, the force down is 1/2 mg (we are doing only one side, due to symettry). The other force is tension, along the wire.
Looks like sinSag=1/2 mg/tension and...
use the second dto find angle Sag, and the first to solve for tension.
how much tension the birdroduce in the wire?