Answer:
3900
Explanation:
Thickness of the thin layer of paint =
m.
Thickness of the coin =
m.
To find out how many layers of paint are in a stack that is the height of the coin, we simply divide the thickness of the coin by the thickness of each thin layer of paint.
Number of Layers
![=(3.51 X 10^(-3))/(9X10^(-7))](https://img.qammunity.org/2021/formulas/mathematics/college/zvybtkg86e0u95d47aw57wkjrdvprk6klj.png)
![=(3.51 )/(9)X 10^(-3-(-7))\\=0.39X10^(-3+7)\\=0.39X10^4\\=3900](https://img.qammunity.org/2021/formulas/mathematics/college/3w328zmuohlnikb4ii1vzs80az8ky9z5ju.png)