Question

shows a piece of block is 15 cm long, 7 cm wide and 3 cm thick is floating with one-third of its volume above the water level. Calculate the buoyant force exerted on the block.

Answer 1

Given:

$V=\rm (15\:cm)\times(7\:cm)\times (3\:cm)=315\; cm^3$

$V_s=2/3V=\rm 210\; cm^3=2.1*10^{-4}\:m^3$

$\rho=\rm 1000\:kg/m^3$

The buoyant force

$$F_b=g\rho V_s=9.8*1000*2.1*10^{-4}=2.06\: \rm N$$