Body A weighing 40 g was combined with body B weighing 80 g with a volume of 40 cm3.
Body A weighing 40 g was combined with body B weighing 80 g with a volume of 40 cm3. Both bodies were placed together in a measuring cylinder filled with water. When completely immersed in water, the bodies were displaced by 140 cm3 of water. determine the density of the body A.
Task data: ma (body weight A) = 40 g = 0.04 kg; mw (body weight B) = 80 g = 0.08 kg; Vw (body volume B) = 40 cm3 = 40 * 10-6 m3; Vzh (volume of displaced water) = 140 cm3 = 140 * 10-6 m3; bodies A and B are completely submerged in water.
Constants: ρw (fresh water density) = 1000 kg / m3; g (acceleration due to gravity) ≈ 10 m / s2.
1) We calculate the total force of Archimedes: Fa = Pzh = ρw * Vzh * g = 1000 * 140 * 10-6 * 10 = 1.4 N.
2) Calculate the Archimedes force acting on the body A: Faa = Fa – Fav = 1.4 – ρw * g * Vw = 1.4 – 1000 * 10 * 40 * 10-6 = 1 N.
3) Find the density of the body A: Faa = ρw * g * V = ρw * g * ma / ρa, from where we express: ρa = ρw * g * ma / Faa = 1000 * 10 * 0.04 / 1 = 400 kg / m3 …
Answer: Body A has a density of 400 kg / m3.