A lump of iron of mass $5\mathrm{.}643$ kg is suspended $($completely immersed$)$ in a brine solution of density $1085$ kg m $-3$

$$ The volume of the iron is $0\mathrm{.}000717$ m $3.$

Calculate the upthrust on the iron object in N $($to $3$ d$.$p$.)$ given g $=9\mathrm{.}81$ ms $2$