quick "physics" question

[Citation]

I recieved this question in my physics class and I cant seem to come up with the correct anwser.


A severe thunderstorm dumped 1.3 in of rain in 15 min on a town of area 24.3 km^2. What mass of water fell down during this thunderstorm.

there is an anwser box followed by X 10^9 kg

This is what I have tried so far...
I am going under the assumption that the time is irrelivant. I have tried converting in's to cm's and then the 24.3 to cm's ^2 and multiplying together to come up with cm's ^3 and then since 1g = 1cm^3, switching to grams and then converting to kg and returning an anwser of something like .000802 X10^9 kg .... any help is greatly appreciated. I also read that 1 m^3 = 1000kg, that might help aswell. Thanks

 

[Heisenberg]

Not sure about the numbers but your method sounds okay. Find the volume and use the density of water (1 g/mL) to calculate the mass.

 

[wfbberzerker]

remember, when converting square kilometers to centimeters, you have to multiply by 100,000 squared (since 1km = 1000 meters, 1km squared = 1000x1000 meters squared; 1m = 100cm, 1m^2 = 100x100 cm^2 ------ therefore 1km^2 = 100,000x100,000 cm^2)

convert inches to centimeters (i think its 2.5cm to the inch or something close) = 3.25cm of rain
convert square kilometers to centimeters = 243,000,000,000cm^2
multiply together = 789,750,000,000
1 cm^3 equals = 1gram

i get... 789.75 X 10^9 grams

edit: clarified numbers a tad

 

[agnitrate]

do your own homework. lazy.

-silver

 

[Citation]

well thank you very much wfbberzerker, your conversion was slightly off and there are 100,000 cm to a km, but you pointed out the obvious flaw of my failing to square my conversion, thanks a ton, i did finally get it, figures it was a simple slip up. Thanks again for your help=)

 

[wfbberzerker]

Originally posted by: Citation
well thank you very much wfbberzerker, your conversion was slightly off and there are 100,000 cm to a km, but you pointed out the obvious flaw of my failing to square my conversion, thanks a ton, i did finally get it, figures it was a simple slip up. Thanks again for your help=)

yah, i meant 100,000 😀

 

[agnitrate]

reserved for editing

[EDIT] I hate you [/EDIT]

-silver

 

[Citation]

Originally posted by: agnitrate
do your own homework. lazy.

-silver

I can't wait till its 6:30 again and i get to turn over and pass out again while you suffer walking to class, Bwahahahaha. Can you even see where your going in the dark like that?


-Cit

 

[wfbberzerker]

Originally posted by: Citation

Originally posted by: agnitrate
do your own homework. lazy.

-silver

I can't wait till its 6:30 again and i get to turn over and pass out again while you suffer walking to class, Bwahahahaha. Can you even see where your going in the dark like that?


-Cit

you know youre jealous that he only goes to class a few times a week, while youre stuck with the 40-hour workweek-like ritual

 

[no0b]

Originally posted by: wfbberzerker
remember, when converting square kilometers to centimeters, you have to multiply by 100,000 squared (since 1km = 1000 meters, 1km squared = 1000x1000 meters squared; 1m = 100cm, 1m^2 = 100x100 cm^2 ------ therefore 1km^2 = 100,000x100,000 cm^2)

convert inches to centimeters (i think its 2.5cm to the inch or something close) = 3.25cm of rain
convert square kilometers to centimeters = 243,000,000,000cm^2
multiply together = 789,750,000,000
1 cm^3 equals = 1gram

i get... 789.75 X 10^9 grams

edit: clarified numbers a tad

Simpler explanation

Find volume then multiply it by the ratio of mass / vol of water. time is not a factor

 

[Legendary]

Originally posted by: no0b

Originally posted by: wfbberzerker
remember, when converting square kilometers to centimeters, you have to multiply by 100,000 squared (since 1km = 1000 meters, 1km squared = 1000x1000 meters squared; 1m = 100cm, 1m^2 = 100x100 cm^2 ------ therefore 1km^2 = 100,000x100,000 cm^2)

convert inches to centimeters (i think its 2.5cm to the inch or something close) = 3.25cm of rain
convert square kilometers to centimeters = 243,000,000,000cm^2
multiply together = 789,750,000,000
1 cm^3 equals = 1gram

i get... 789.75 X 10^9 grams

edit: clarified numbers a tad

Simpler explanation

Find volume then multiply it by the ratio of mass / vol of water. time is not a factor

I believe that is exactly what is shown.

 

[Howard]

1 cm^3 of water =1g only if the water is 4 degrees C.

 

[wfbberzerker]

Originally posted by: no0b

Originally posted by: wfbberzerker
remember, when converting square kilometers to centimeters, you have to multiply by 100,000 squared (since 1km = 1000 meters, 1km squared = 1000x1000 meters squared; 1m = 100cm, 1m^2 = 100x100 cm^2 ------ therefore 1km^2 = 100,000x100,000 cm^2)

convert inches to centimeters (i think its 2.5cm to the inch or something close) = 3.25cm of rain
convert square kilometers to centimeters = 243,000,000,000cm^2
multiply together = 789,750,000,000
1 cm^3 equals = 1gram

i get... 789.75 X 10^9 grams

edit: clarified numbers a tad

Simpler explanation

Find volume then multiply it by the ratio of mass / vol of water. time is not a factor

i figure he'll understand it better if i show it. besides i wanted to show that when converting magnitudes, you need to remember the powers when you multiply, which was what he forgot.