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Grade upto college level Mechanics

Why does the factor 2 appear in Eq. 16-15, rather than 1? One might naively expect that the thrust would simply be the pressure difference times the area − that is, A0(p – p0).

Profile image of Shane Macguire
11 Years agoGrade upto college level
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Profile image of Deepak Patra
11 Years ago
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The above expression is deduced using Bernoulli’s equation. The equation states that the total energy of the gas per unit volume which is equal to the sum of the kinetic energy per unit volume, potential energy per unit volume and the pressure of the gas remains constant. The factor 2 comes from the kinetic energy per unit volume of the exhaust gas. It shows that the thrust on the rocket is 2 times the area of the orifice times the pressure difference of the gas between the inside and outies chamber.