The distance between two telephone poles is 42 m. When a 1.44 kg bird lands on the telephone wire midway between the poles, the wire sags 0.139 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.

To find the tension in the wire produced by the bird, we can use the formula for gravitational force:

F = mg

Where:
F = Force (tension in the wire)
m = mass of the bird (1.44 kg)
g = acceleration due to gravity (9.8 m/s^2)

However, we need to find the net force that causes the wire to sag. The net force due to a sagging wire is equal to the gravitational force pulling the bird down.

Considering the wire sags by 0.139 m, we can use the formula for the force due to a sagging wire:

F = (1/2)mg

Now let's substitute the values into the formula to calculate the tension in the wire:

F = (1/2)(1.44 kg)(9.8 m/s^2)
F = 0.5(1.44 kg)(9.8 m/s^2)
F = 7.056 N

Therefore, the tension in the wire produced by the bird is approximately 7.056 N.

To calculate the tension in the wire produced by the bird, we can use the concept of equilibrium. We know that the weight of the bird pulling downwards is balanced by the tension in the wire pulling upwards.

First, let's find the weight of the bird using the formula:

Weight = mass × acceleration due to gravity
Weight = 1.44 kg × 9.8 m/s^2

Weight = 14.112 N

Since the wire sags in a parabolic shape, we can assume that the sag is half of the total sag between the two poles. Therefore, the total sag between the two poles is:

Total Sag = 2 × 0.139 m
Total Sag = 0.278 m

Now, let's consider a small section of the wire between the bird and one of the poles. The tension in the wire is not constant along the entire length but gradually increases from the pole to the bird.

Using the concept of equilibrium, we can consider the forces acting on this small section of the wire:

1. Tension force pulling upwards
2. Weight of the bird pulling downwards
3. Force due to the horizontal component of tension (negligible for a small section)

The net force in the vertical direction is zero because the wire is not accelerating:

Net Force = Tension - Weight = 0

Therefore,

Tension = Weight

Tension = 14.112 N

Hence, the tension in the wire produced by the bird is approximately 14.112 N.