The mass of an empty 40 litre petrol tank of a vehicle is 8.0 kg What will be its mass when filled completely with a fuel of density `700(kg)/(m^3)`.

Explanation

`V=40`litres`=40xxx10^-3m^3`
`d=700(kg)/(m^3)`
`d=700(kg)/(m^3)`
M(mass of petrol)`=Vxxd=(40xx10^-3m^3)xx(700(kg)/(m^3))=28kg`
m(mass of empty petrol tank)`=8kg`
Mass of the tank filled with petrol `=M+m=28kg+8kg=36kg`