The aluminum foil in a package containing 75 square feet of foil weighs 12 ounces. aluminum has a density of 2.70 g/ cm3. what is the approximate thickness of the foil in mm?

Solution:

Since we know that 1 ounce=28.4g/oz

So for 12 oz  X  28.4 g/oz  =  340.8 g

And,

 340.8 g  X  1cm3/2.7g  =  126.22 cm3

Again,

75 ft2  X  12 in/ft  X  12 in/ft  X  2.54 cm/in  X  2.54 cm/in  =  69,677.28 cm2  

(Here ft^2=ft*ft)

Now,

69,677.28 cm2  X Thickness  =  126.22 cm3

Finally Solve for Thickness: 126.22 cm3 / 69,677.28 cm2  =  0.00181 cm

Thus for mm we have to:

0.00181 cm  X  10 mm/1 cm  =  0.0181 mm.

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