# Question #bec07

##### 1 Answer

#### Explanation:

As you know, density is defined as mass *per unit* of volume.

#color(blue)("density" = "mass"/"volume")" "# , or#" "color(blue)(rho = m/V)#

In your case, you know that the mass of the leather belt if equal to

Well, your belt is actually a **rectangular prism** for which you know that

its length is equal to#"98 cm"# its width is equal to#"3.5 cm"# its height is equal to#"0.4 cm"#

The volume of a rectangular prism can be calculated using the formula

#color(blue)(V = l xx g xx h)#

In your case, the volume of the belt will be equal to

#V = "98 cm" xx "3.5 cm" xx "0.4 cm" = "137.2 cm"^3#

Therefore, you can now say that its density is equal to

#rho = "130 g"/"137.2 cm"^2 = "0.9475 g/cm"^3#

You *should* round this off to one sig fig, the number of sig figs you gave for the height of the belt, but I'll leave it rounded to two sig figs

#rho = color(green)("0.95 g/cm"^3)#