A piece of corroded steel plate was found in a submerged ocean vessel. It was estimated that the original area of the plate was 11 in.2 and that approximately 2.3 kg had corroded away during the submersion. Assuming a corrosion penetration rate of 200 mpy for this alloy in seawater, estimate the time of submersion in years. The density of steel is 7.9 g/cm3.

The time of the submersion is

Explanation:

From the question we are told that

   The area of the plate is  

    The mass of the corroded plate

    The corrosion penetration rate is

     The density of steel is  

Generally the corrosion penetration rate   can be mathematically represented as

Where K is the corrosion imperial unit constant   whose value is  K = 534 mpy

           t is the exposure time of the plate

   Making t the subject of the formula

      Substituting value

Converting to years

a straight line sloped