Question

Suppose you are measuring the mass of a sample using a balance that employs a standard mass of density dw = 8.0 g/ml. what is the buoyancy correction (m/m\'), if the sample density is less than 8.0 g/ml?

Answer 1

The buoyant force formula is:

`B = \rho Vg`

where
`B` is Buoyant force,
`\rho` is density,
`V` is displaced body volume and
`g` is
`9.806 ms^(-2)` (standard gravity).

The standard mass density of the sample,
`\rho _(1)` =
`8 g/ml`

If the dansity of the sample,
`\rho _(2)`
`< 8 g/ml`

The buoyancy correction is determined by the ratio:

`(B_(1))/(B_(2)) = (\rho_(1) Vg)/(\rho_(2) Vg)`

`(B_(1))/(B_(2)) = (\rho_(1))/(\rho_(2))`

`(B_(1))/(B_(2)) = (\rho_(1))/(\rho_(2))>1`

Hence, the the buoyancy correction is positive.