Posted by laura on Saturday, September 5, 2009 at 10:23pm.
an average family of four uses roughly 1200 liters (about 300 gallons) of water per day (1 liter=1ooocm cubed) . how much depth would a lake lose per uear if it uniformly covered an area of 50 square kilometers and supplied a llocal town with a population of 40,000 people 
this is from a textbook, but I do know which one it is

math  MathMate, Saturday, September 5, 2009 at 10:54pm
Calculate the volume used per year, V, in cubic metres. Note that there are 1000 l. in 1 m³.
Calculate the surface area of the lake in square metres, A.
The decrease in depth, D, is V/A metres, assuming no river feeds the lake, and no change in volume due to evaporation and rain.
V=1200 (l.)/1000 (l/m³)*40000 (people) * 365 (days)
=1200/1000*40000*365 m³
S=50 (km²)=50*1000*1000 (m²)
Calculate V, S and D=V/S

Physics  Alex, Wednesday, September 3, 2014 at 7:34pm
50,000,000 sq m
1.2x10,000 (10,000 families of 4 = 40,000 people)
12,000 m^3 per day * 365 days = 4,380,000 m ^3 per year
Depth = 4,380,000 m ^3 / 50,000,000
Depth lost = 0.0876 m^3
Answer This Question
Related Questions
 Physics  An average family of four uses roughly 1200 liters (300 gallons) of ...
 Physics  An average family of four uses roughly 1600 liters (about 400 gallons...
 MTH/208  East Battle Lake in Minnesota covers an area of about 1950 acres or 8....
 math  East Battle Lake in Minnesota covers an area of about 1950 acres or 8....
 Algebra Please Help  I am doing Unit Analysis and I can not fugure out how to ...
 Algebra Unit Analysis  I am doing Unit Analysis and I can not fugure out how ...
 AP Environmental Science  I'm confused about how to do these problems, I ...
 Engineering Economics  Sales of bottled water in the U.S totaled 16.3 gallons ...
 math  The population of the US is about 3.02 X 10^8, and the average American ...
 math  The federal government estimated that 2,000,000 gallons of oil were ...
More Related Questions