The communicating vessels contain mercury. The diameter of one vessel is twice the size of the other.
The communicating vessels contain mercury. The diameter of one vessel is twice the size of the other. A column of water 0.7 meters high is poured into a narrow vessel. How much will the level of mercury rise in one vessel and drop in another?
Data: hw (height of the poured water column) = 0.7 m; db (diameter of the larger vessel) = 2dm (diameter of the smaller vessel).
Constants: ρw (water density) = 10 ^ 3 kg / m3; ρrt (density of mercury) = 13.6 * 10 ^ 3 kg / m3.
1) The ratio of changes in mercury levels in vessels: Sb * hb = Sm * hm, from where we express: hm = Sb * hb / Sm = (0.25 * Π * db ^ 2) * hb / (0.25 * Π * dm2 ) = (2dm2) * hb / dm2 = 4hb.
2) Change in the height of mercury in the larger vessel: ρw * g * hw – ρrt * g * hm = ρrt * g * hb; ρw * g * hw = ρрт * g * hb + ρрт * g * hм; ρв * hв = 5ρрт * hb, whence we express: hb = ρв * hв / (5 * ρрт) = 10 ^ 3 * 0.7 / (5 * 13.6 * 10 ^ 3) = 0.01 m = 1 cm …
3) Change in the height of mercury in a smaller vessel: hm = 4hb = 4 * 1 = 4 cm.
Answer: Mercury will descend in a smaller vessel by 4 cm and rise in a larger one by 1 cm.