An infinitely long straight wire has a uniform linear charge density of derive the 4. equation for the electric field a distance r away from the wire using gauss's law for electrostatics.

Explanation:

Let the linear charge density of the charged wire is given as

here we can use Gauss law to find the electric field at a distance r from wire

so here we will assume a Gaussian surface of cylinder shape around the wire

so we have

here we have

so we have

answer; equivalent to a one(1) horsepower motor;

d. air pressure decreases as altitude increases.