Answer
(a) $0.008m^3$
(b) $18N$
Work Step by Step
(a) The required volume can be determined as follows:
$V=V_{\circ}(1-\frac{\rho_p}{\rho_w})$
We plug in the known values to obtain:
$V=(0.089m^3)(1-\frac{910Kg/m^3}{1000Kg/m^3})$
$\implies V=0.008m^3$
(b) We know that
$F=\rho_{water}.\Delta V.g$
We plug in the known values to obtain:
$F=(1000Kg/m^3)(0.0018m^3)(9.81m/s^2)$
$F=18N$
