Question 212578: One cubic millimeter of oil is spread on the surface of the water so that the surface of water so that the oil film has an area of 1 square meter.
What is the thickness of the oil film in angstrom units?
Found 2 solutions by Alan3354, rapaljer:
Answer by Alan3354(69443)   (Show Source):
You can put this solution on YOUR website! One cubic millimeter of oil is spread on the surface of the water so that the surface of water so that the oil film has an area of 1 square meter.
What is the thickness of the oil film in angstrom units?
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1 sq meter = 1,000,000 sq mms
Vol = Area*thickness
1 mm^3 = 1000000*t
t = 0.000001 mm = 1E-6 mm
1 Angstrom = 1E-10 meters = 1E-7 mms
t = 10 Angstroms
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Angstrom is not in common use any more, nanometers are more common.
nano = billionth = 1E-9
We use meters, millimeters, microns (1 millionth of a meter), nanometers, picometers.
Answer by rapaljer(4671)  (Show Source):
You can put this solution on YOUR website! First an Angstrom = 1 ten billionth of a meter. That is 1/10,000,000,000 of a meter. (By the way, I didn't know that! I had to look it up!!)
The oil is going to form what is essentially a "cylinder" as it spreads out in a circle, with a radius, and a VERY small thickness (or height!). What you want to find is the height of the cylinder, given that the volume is 1 cubic millimeter and the AREA of the circle is 1 square meter.
The formula for the volume of a cylinder is V = Area * Height.
In this case, it will be V=Area*Thickness, where V=1 cu mm, A=1 sq m, Thickness = x, the unknown.
In order to get the same units, convert 1 cu mm to cu m. First 1 mm = .001 m, so 1 mm^3 = .001^3 m^3. In scientific notation 
V=Area*Thickness
1 cu mm = 10^-9 cu m = 1 sq m * x m
Turn it around! It will look better:
 cu m
 m (Square meters divides into cubic meters leaving meters for the correct unit!)
Now convert this to Angstroms, where 1 Angstrom = 10^-10 meters.
Multiply both sides of the above equation by 10:
10 Angstroms = 10* 10^-10 meters = 10^-9, and that is exactly what you have!
10 Angstroms should be the final answer. Wow! Where did you get THAT problem??? Somebody send me an email if I'm wrong!!
R^2
Dr. Robert J. Rapalje, Semi-retired
Seminole Community College
Altamonte Springs, FL 32714
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