A fish tank holds 35 gallons of water. How many pounds (lb) of water are in the fish...

[megami]

the first thing you need is the density of water, which is 1 g/ml or 1g/cm^3. so from here you convert the gallons of water into milliliters:
1gal=3.7854L=3785.4mL. So 35gal x 3785.4ml/1gal =132489mL
and remember density is D=M/V, or in this case you can manipulate it to be M=DV (where M is mass, V is volume, and D is density) if D=1g/ml , and V=132489ml you multiply them together to get M. the mL will cancel out. so 1g/mL x132489mL = 132489g.

now convert the grams to pounds: 1Lb = 453.59g. so set it up as 132489g x (1Lb/453.59g). meaning divide the amount you have by 453.59. so 132489g x (1Lb/453.59g)= 292.0897727Lb

now if you are worrying about sig figs you will round it to 290Lb or 2.9x10^2Lb. hope this helps


or you could do it like the ppl above me said lol

[unorthodoxnerdperson]

lol, the one thing the Europeans have on us, a measurement system where it all works out.
But seriously google the weight per pound and multiply..sigh

Btw 35 by 8.32 is 291.2, check your rounding lol

but in all seriousness and helpfulness, did you mean significant figures, where you would round to 290lbs?

Or did you mean the annoying GUESS process?
Givens, Unknowns, Equation, Substitute, Solve
G:35 gallons of water
U:weight in lbs
E:weight=(gallons)x(lbs per gallons)
S:weight=(35)x(8.32) [working off your numbers chief]
S:weight=291.2, which mysteriously rounds to 292, but for sig figs 290

and finally you would put [290lbs].......all niced and boxed of course

[unorthodoxnerdperson]

lol, the one thing the Europeans have on us, a measurement system where it all works out.
But seriously google the weight per pound and multiply..sigh

Btw 35 by 8.32 is 291.2, check your rounding lol

but in all seriousness and helpfulness, did you mean significant figures, where you would round to 290lbs?

Or did you mean the annoying GUESS process?
Givens, Unknowns, Equation, Substitute, Solve
G:35 gallons of water
U:weight in lbs
E:weight=(gallons)x(lbs per gallons)
S:weight=(35)x(8.32) [working off your numbers chief]
S:weight=291.2, which mysteriously rounds to 292, but for sig figs 290

and finally you would put [290lbs].......all niced and boxed of course

[ash]

1 gallon= 8.345 lbs. Do the math.