How Much Water Fell on the City During the Storm?

AI Thread Summary
A rainstorm deposited 1.7 cm of rain over a city measuring 4.0 km by 7.0 km in two hours. The volume of water calculated was 4.76E7 cm^3, leading to an initial mass estimate of 47.6 metric tons. However, the calculations were incorrect due to improper unit conversions from kilometers to centimeters. Once the correct conversions were applied, the accurate mass of water was determined. The discussion highlights the importance of careful unit conversion in calculations.
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Homework Statement


A violent rainstorm dumps 1.7 cm of rain on a city 4.0 km wide and 7.0 km long in a 2.0 hr period. How many metric tons of water fell on the city?

Homework Equations



1 ton = 10^3 kg
1 cm^3 of water has a mass of 1 g = 10^-3 kg.
Density of water is 1.0 g/cm^3

The Attempt at a Solution



Knowing that density of water is 1.0 g/cm^3...

I first calculated the volume, which is v = (1.7 cm) (4000 cm) (7000 cm) = 4.76E7 cm^3. To get the mass in metric tons, I did the following: mass = (4.76E7 cm^3) (1 g/cm^3) (1 kg / 1 000 g) (1 metric ton / 1000 kg) = 47.6 metric tons.

When I entered it into the computer, it said it was incorrect. Please help!
 
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If 1 metre = 100 cm and 1 km = 1000 m, then 4.0 km = how many cm??
And for 7.0 km??
 
Wow. Thanks, man. I messed up the conversion factor. No wonder why I keep getting it wrong. lol Thanks again! I don't know how I could have missed that!
 
Last edited:
Finally got it!
 

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