Question

A cubical block is dipped completely in water. Each edge of the block is 1 cm in length. Find the buoyant force.

Answer 1

The buoyant force acting on an object submerged in a liquid is
F = ρgV
where
ρ is the density of the liquid (here its water so ρ is known)
g is the acceleration due to gravity and
V is the volume of the submerged object or displaced liquid (= mass/volume)
Here,
$\rho =1000kg/m^3$
$g=9.81m/s^2$ and

V (for cube of 1 cm length) = 1 cm x 1cm x 1cm = $1c{m}^3={10}^{-6}{m}^3$
Thus, we have
$F=1000\times 9.81\times {10}^{-6}$
or buoyant force will be
F = 0.00981 N.