(a).
density of fresh water is ρ_water = 1000 kg/m³
ΣF = 0
- (ρ_wood)g(V_wood) + (ρ_water)g(v_wood) = 0
(v_wood)/(V_wood) = (ρ_wood)/(ρ_water)
(10 * 10 * h)/(10 * 10 * 10) = (700)/(1000)
h = 7 cm
the distance from the top of the block to the water is 10 - 7 = 3 cm
(b).
density of seawater is ρ_sea = 1030 kg/m³
(v_wood)/(V_wood) = (ρ_wood)/(ρ_sea)
(10 * 10 * h')/(10 * 10 * 10) = (700)/(1030)
h' = 6.79611 cm
the distance from the top of the block to the water is 10 - 6.79611 = 3.20389 cm
