C++

The resistance of a cylindrical conductor made either from copper, aluminum, or manganese is given by R=pl/A in ohm meter where the resitivity p of the conductor for the different material is given as 1.8e-10, 2.5e-10, and 1.5e-06, respectively. The length l is in meters and area A is in square meters. The user will input the material, area, and the required resistance of the conductor and your program will output the length of the conductor.