SO₁ =O₁O₂=O₂O ; Vкон =V =27.
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ΔV = (V₂ - V₁) -?
Обозначаем SO =3h ⇒ SO₁ =h₁ =h ; SO₂ =h₂ =2h .
ΔV = V₂ - V₁ .
V =(1/3)*πR²*(3h) =πR²h.
V₁=(1/3)*πR₁²*h₁=(1/3)*π(R/3)²*h =(1/27)πR²h =(1/27)V. | (1/3)³V |
V₂=(1/3)*πR₂²*h₂=(1/3)*π(2R/3)²*2h =(8/27)πR²h =(8/27)V. | (2/3)³V |
ΔV = V₂ - V₁ = (8/27)V -(1/27)V =(7/27)*27 =7.
ответ : 7.
* * * P.S. R₁/R =SO₁/SO =1/3 ; R₂/R =SO₂/SO =2/3 из под. Δ-ов * * *