Question #228b4

1 Answer
Sep 8, 2017

Answer:

#"100 cm"^3#

Explanation:

The thing to remember about the density of a substance is that it's supposed to tell you the mass of exactly #1# unit of volume of that substance.

In your case, the boulder is said to have a density of #"8 g/"color(blue)("cm"^(3))#, which means that #color(blue)("1 cm"^3)# of this boulder has a mass of #"8 g"#. In other words, every time you have a mass of #"8 g"# of this boulder, the sample will occupy #color(blue)("1 cm"^3)#.

You can thus use the density of the boulder as a conversion factor to calculate the volume of the #"800-g"# sample

#800 color(red)(cancel(color(black)("g"))) * overbrace(color(blue)("1 cm"^3)/(8color(red)(cancel(color(black)("g")))))^("the given density = 8 g/"color(blue)("cm"^3)) = color(darkgreen)(ul(color(black)("100 cm"^3)))#

The answer is rounded to one significant figure.

So remember, when a problem provides you with the density of the substance, it's essentially giving you the mass of exactly #1# unit of volume of that substance.