By definition, the density is given by:
[tex] D = \frac{m}{V} [/tex]
Where,
m: mass
V: volume
Clearing the mass we have:
[tex] m = DV [/tex]
The volume is given by:
[tex] V = (8) * (7) * (0.75) [/tex]
[tex] V = 42ft ^ 3 [/tex]
Then, we have the following conversion:
[tex] 1foot = 0.3048m [/tex]
Applying the conversion we have:
[tex] V = 42 * (0.3048) ^ 3 [/tex]
[tex] V = 1.19m ^ 3 [/tex]
On the other hand we have the following conversions:
[tex] 1m = 100cm [/tex]
[tex] 1Kg = 1000g [/tex]
Applying the conversions for the density we have:
[tex] D = (1\frac{g}{cm^3})((\frac{100}{1})^3\frac{cm^3}{1m^3})(\frac{1}{1000}\frac{Kg}{g})=1000\frac{Kg}{m^3} [/tex]
Then, the mass of the water is:
[tex] m = (1000) * (1.19) [/tex]
[tex] m = 1190 [/tex]
Answer:
1190 kilgrams of water are required to fill the waterbed
