Question

Calculate the true mass (in vacuum) of a piece of aluminum whose apparent mass is 4.5000 kgkg when weighed in air. The density of air is 1.29 kg/m3kg/m3, and the density of aluminum is 2.7×103kg/m32.7×103kg/m3.

Answer 1

The true weight of the aluminium is
`m_(alu) =` 4.5021 kg

Step-by-step explanation:

Given data

`m_(app)` = 4.5 kg

`\rho_(air)` = 1.29
`(kg)/(m^(3) )`

`\rho_(al)` = 2.7×
`10^(3) (kg)/(m^(3) )`

The true mass of the aluminium is given by

`m_(alu) = (\rho_(alu)m_(app))/(\rho_(alu) -\rho_(air) )`

Put all the values in above equation we get

`m_(alu) = ((2700)(4.5))/(2700-1.29)`

`m_(alu) =` 4.5021 kg

Therefore the true weight of the aluminium is
`m_(alu) =` 4.5021 kg