Answer:
A. 2.30 x 10^2 kil
Explanation:
3/2 = 1.5 and 0.72/2 = 0.36
1.93 + 0.36 = 2.29
2.29 = about 2.30
<span>There are several ways to change the frictional force between two objects. The first one is to modify the surfaces of each object that will come in contact with each other. The smoother they get, the less friction there will be. But if the surfaces become rougher, more friction will be generated. If you don’t want to alter the surfaces, you can simply add lubrication to reduce friction.</span>
The resistance of the cylindrical wire is
.
Here
is the resistance,
is the length of the wire and
is the area of cross section. Since the wire is cylindrical
. Rearranging the above equation,

Here
.
Substituting numerical values,

The length of the wire is 
Exosphere is the answer . I have done this lesson in my physics class it's exosphere.