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The quantity Lighthill referred to as the 'virtual mass' is usually called 'added mass' in ocean engineering and naval architecture. It is basically the force on the body due to its acceleration in the fluid. The term 'added' is a bit misleading, as in certain cases, it can be negative. Note that the added mass depends also on the mode of motion. So, for ...


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As David said, in a rocket the final velocity is given by a function that grows logarithmically (i.e: really slowly) with the ratio between the mass of the rocket with and without fuel (the so-called dry mass). So if you somehow make your fuel carrying capacity a hundred times larger than the mass of the empty ship, you only increased your final velocity by ...


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Why can't a space ship accelerate infinitely? Because a space ship needs to carry fuel, and because that fuel needs to be contained in a fuel tank. That need to carry the fuel needed to make the spacecraft accelerate leads to the very nasty ideal rocket equation, $$\Delta v = v_e \ln \left( \frac {m_{\text{initial}}} {m_{\text{final}}} \right)$$ The ...


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The maximum theoretical speed that a spaceship can reach isn't limited by anything (except the speed of light of course). However for a practical spaceship with a finite amount of fuel, the speed of the exhaust will set a practical maximum on the speed of the spaceship. This is because in order to accelerate to a higher speed, the spaceship would have to ...


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Theoretically, the radial distribution should be symmetric. However, in jets in general it is well know that there will be a transition from purely laminar (i.e. symmetry preserving) to purely turbulent (breaks the symmetry). Have a look at this video. The presence of the plasma induces the turbulence at much earlier in space compared to when it is absent. ...



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