Copper, because it has the lowest specific electrical resistance.
specific electrical resistance aka volume resistivity is a fundamental property of a material that quantifies how strongly that material opposes the flow of electric current. A low resistivity indicates a material that readily allows the flow of electric current.
Answer:
The net torque is zero
Explanation:
Let's assume that the dipole is compose of two equal but oposite charges e, and it cam be represented by a rod with one end having a charge e and the other end with a charge of -e. Notice that the dipole is parallel to the electric field thus the force felt by both of the charges will be parallel to the electric field. This means that there will be no components of the forces that are perpendicular to the rod which is a requirement for it to have a torque.
Sum of all forces = mass * acceleration
Ft= tension force
Fw= force of gravity (Fw= mass* acceleration of gravity which is 9.8 this only applies to force of gravity)
Ft- Fw = 0 (there is no acceleration)
Ft = Fw
Ft= m*g
Ft= 0.250kg*9.8m/s
Ft= 2.45N
We have the equation of motion 
, where s is the displacement, a is the acceleration, u is the initial velocity and t is the time taken.
Here displacement = 135 m, Initial velocity = 0 m/s, acceleration = 9.81 
Substituting
A box falls out of a stationary helicopter hovering 135 m above the ground will take 5.25 seconds to reach the ground.
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
