Question

A stone of density 3000 kg/m3 is lying submerged in water of density 1000kg/m3 if the mass of the stone in air is 150 kg calculate the force required to lift the stone

Answer 1

Density of stone ρ = 3000 kg/m^3

Density of Water = 1000 kg/m^3

Mass of stone m = 150 kg

Vol. of stone = m / ρ = 150 / 3000 = 1/20=0.05 m^3

F = Vol. of stone * Vol. of water * g
= 0.05 * 1000 * 9.81
= 490.5 N