I think it’s C but not sure..
Weight = mg Mass, m = 8kg, g ≈ 9.8 m/s² on Earth
W = 8*9.8
W ≈ 78.4 N
Answer:
Therefore the rate of corrosion 37.4 mpy and 0.952 mm/yr.
Explanation:
The corrosion rate is the rate of material remove.The formula for calculating CPR or corrosion penetration rate is
![CPR=\frac{KW}{DAT}](https://tex.z-dn.net/?f=CPR%3D%5Cfrac%7BKW%7D%7BDAT%7D)
K= constant depends on the system of units used.
W= weight =485 g
D= density =7.9 g/cm³
A = exposed specimen area =100 in² =6.452 cm²
K=534 to give CPR in mpy
K=87.6 to give CPR in mm/yr
mpy
![CPR=\frac{KW}{DAT}](https://tex.z-dn.net/?f=CPR%3D%5Cfrac%7BKW%7D%7BDAT%7D)
![=\frac{534\times( 485g)\times( 10^3mg/g)}{(7.9g/cm^3) \times (100in^2)\times (24h/day)\times (365day/yr)\times 1yr}](https://tex.z-dn.net/?f=%3D%5Cfrac%7B534%5Ctimes%28%20485g%29%5Ctimes%28%2010%5E3mg%2Fg%29%7D%7B%287.9g%2Fcm%5E3%29%20%5Ctimes%20%28100in%5E2%29%5Ctimes%20%2824h%2Fday%29%5Ctimes%20%28365day%2Fyr%29%5Ctimes%201yr%7D)
=37.4mpy
mm/yr
![CPR=\frac{KW}{DAT}](https://tex.z-dn.net/?f=CPR%3D%5Cfrac%7BKW%7D%7BDAT%7D)
![=\frac{87.6\times (485g)\times (10^3 mg/g)}{(7.9g/cm^3)\times (100in^2)\times(2.54cm/in)^2\times (24h/day)\times (365day/yr)\times 1yr}](https://tex.z-dn.net/?f=%3D%5Cfrac%7B87.6%5Ctimes%20%28485g%29%5Ctimes%20%2810%5E3%20mg%2Fg%29%7D%7B%287.9g%2Fcm%5E3%29%5Ctimes%20%28100in%5E2%29%5Ctimes%282.54cm%2Fin%29%5E2%5Ctimes%20%2824h%2Fday%29%5Ctimes%20%28365day%2Fyr%29%5Ctimes%201yr%7D)
=0.952 mm/yr
Therefore the rate of corrosion 37.4 mpy and 0.952 mm/yr.