Answer:
Therefore,
The magnitude of the force per unit length that one wire exerts on the other is

Explanation:
Given:
Two long, parallel wires separated by a distance,
d = 3.50 cm = 0.035 meter
Currents,

To Find:
Magnitude of the force per unit length that one wire exerts on the other,

Solution:
Magnitude of the force per unit length on each of @ parallel wires seperated by the distance d and carrying currents I₁ and I₂ is given by,

where,

Substituting the values we get


Therefore,
The magnitude of the force per unit length that one wire exerts on the other is

The same bird on the tree has more gravitational potential energy. This is because it is at a higher distance from the ground as it is on the tree, than when it is on the ground.
Considering also the formula for Gravitational Potential Energy GPE = mgh
For the bird on the ground, h =0, therefore GPE = m*9.8*0 = 0
For that on the tree = mgh = m*9.8*h
Of course the one on the tree has a value greater than zero.