The relationship between resistance R and resistivity

is

(1)
where L is the length of the wire and A is the cross-sectional area.
In our problem, the radius of the wire is half the diameter: r=1 mm=0.001 m, so the cross-sectional area is

The length of the wire is L=20 m and the resistance is

.
By re-arranging equation (1), we can find the resistivity of the wire:
Answer:
Explanation:
What a lot of words to solve such a simple problem! The perpendicular force is the one that is pushing straight down on the plane. There is no side to side movement here or friction acting on this dimension at all. Perpendicular force is the same as the weight of the block. That's it! Perpendicular force is also normal force which is the same thing as weight:
w = mg so
w = (4.04)(9.8) and
w = 4.0 × 10¹ N
The correct option is D.
According to special relativity, in no frame of reference does light in a vacuum travel at less than the speed of light, the speed of light in a vacuum is the same for any inertial reference frame.This fact remain valid no matter the speed of a light source relative to another observer.
Yes that is a balaned equation