Answer:
825 kgm⁻³
Explanation:
ρ = density of wood = ?
ρ' = density of water = 1000 kgm⁻³
V = volume of wood = 10 x 4 x 2 = 80 cm³ = 80 x 10⁻⁶ m³
V' = Volume of water displaced = 10 x 4 x 1.65 = 66 cm³ = 66 x 10⁻⁶ m³
Using equilibrium of force in vertical direction
Force of buoyancy = Weight of the wood
ρ' V' g = ρ V g
ρ' V' = ρ V
(1000) (66 x 10⁻⁶) = ρ (80 x 10⁻⁶)
ρ = 825 kgm⁻³
