The cream in the middle of a cream-filled donut has a volume of 50 cubic centimeters and a mass of 10 grams. What is the density?

Expert Answers

An illustration of the letter 'A' in a speech bubbles

Hello!

The density of something, by definition, is the the mass m of this something divided by its volume V:

`rho` = m / V.

For heterogeneous objects this is the definition of an average density. For homogeneous substances density doesn't depend on a quantity of a substance used for a measurement. If, say, a volume is increased twice, then the mass will also be twice greater and the density will be the same.

 

In our case, the density is 10 g / 50 cm^3 = 0.2 `g/(cm^3).`

 

A density may be expressed in other units. For example, the standard SI unit is `(kg)/(m^3).` Because 1 kg = 1000 g and 1 m = 100 cm, to convert from `g/(cm^3)` to `(kg)/(m^3)` it is necessary to multiply by `(1/1000) / (1/100^3) = (1,000,000)/(1,000)=1000.`

So, it is also correct to say that the density of the cream is 200 `(kg)/(m^3).`

 

See eNotes Ad-Free

Start your 48-hour free trial to get access to more than 30,000 additional guides and more than 350,000 Homework Help questions answered by our experts.

Get 48 Hours Free Access
Approved by eNotes Editorial