The aluminum in a package containing 64 ft^2 of kitchen foil weighs approximately 12 ounces. Aluminum has a density of 2.70 g/cm^3 . What is the approximate thickness of the aluminum foil in millimeters? (1 ounce = 28.4g)
This problem can look somewhat daunting at first glance, but just start with the information that you have and use it to fill in equations that you have already likely been told in class. I would start with figuring out the total mass.
You have a 12 ounce package. 1 ounce = 28.4 grams. Multiply 28.4 by 12. This means that the total mass of aluminum that you have is 340.8 grams.
You have also been given the density. If you know the total mass and the density, you can calculate volume.
Volume = mass/density
Volume = 340.8 / 2.7
Volume = 126.2 cm^3
126 cubic centimeters is the same as .0044 cubic feet. We need the value in cubic feet in order to use the 64 square feet info provided in the question.
Volume can also be calculated by doing length x width x height.
Length x width is also area in square units. The problem gave you this value as 64 square feet. You are not given an exact length and width, but it doesn't matter. Regardless of the length and width measurements, they equal 64 when multiplied. This gives the following equation.
.0044 = 64 x height
Divide .0044 by 64.
Height = .0000687 ft
1 foot is equal to 304.8 mm, so multiply the height in feet by 304.8 to get the height/thickness of the tin foil in mm.
That value is .02 mm, which is a standard foil thickness.
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