Answer:
3900
Step-by-step explanation:
Thickness of the thin layer of paint = [tex]9X10^{-7[/tex] m.
Thickness of the coin = [tex]3.51 X 10^{-3[/tex] 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[tex]=\dfrac{3.51 X 10^{-3}}{9X10^{-7}}[/tex]
[tex]=\dfrac{3.51 }{9}X 10^{-3-(-7)}\\=0.39X10^{-3+7}\\=0.39X10^4\\=3900[/tex]
