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....
- Engineering Economics - Sales of bottled water in the U.S totaled 16.3 gallons ...
- math - East Battle Lake in Minnesota covers an area of about 1950 acres or 8....
- 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 ...
- Algebra Please Help - I am doing Unit Analysis and I can not fugure out how to ...
- Math (quadratic function) - A fuel station sell, aproximately, 2140 liters of ...
- Algebra Unit Analysis - I am doing Unit Analysis and I can not fugure out how ...