The density of water is 1gm/cm^3. Use the density and these dimensions to find the mass of the water in grams in a fish tank. Use the rules of significant figures and rounding to come up with the correct answer.
30 cm width * .075 meters length * 15 inches high
I got 8572.5 gms for the mass of the water, but I can't figure out how to round the number to 1 sig fig.
8572.5 rounds to 1 s.f. as
9E3.
Not sure what 9E3 means. 9000?
And is my calculation of 8572.5 gms correct?
Your calculation is correct.
9E3 means 9 x 10^3. Obviously you can't write this the usual way because that shows 5 s.f. Rounding one less number at a time gives us 8572, 8570, 8600 and 9000. Since we are allowed only one s.f., that can be written as 9000 (but many misinterpret that number as having 4 s.f. and that can be avoided by writing it as 9 x 10^3 or 9E3 and there no ambiguity about that.
To find the mass of the water in the fish tank, you need to calculate the volume of the tank and then multiply it by the density of water.
First, let's convert the given dimensions to a consistent unit. Since the density of water is given in grams per cubic centimeter, let's convert the dimensions to centimeters:
30 cm width * 75 cm length * 15 cm high
Now, we can calculate the volume of the tank by multiplying the three dimensions together:
V = 30 cm * 75 cm * 15 cm
V = 33,750 cm³
Next, we can use the density of water to find the mass. Remember, density is defined as mass divided by volume:
Density = Mass / Volume
Rearranging the equation, we get:
Mass = Density * Volume
Let's substitute the values:
Mass = 1 g/cm³ * 33,750 cm³
Mass = 33,750 grams
Now, regarding significant figures and rounding. The number 33,750 has five significant figures. When rounding to one significant figure, you should consider the first nonzero digit and round up or down accordingly.
In this case, 33,750 rounded to one significant figure would be 30,000 grams.
So, the mass of the water in the fish tank, rounded to one significant figure, is 30,000 grams.