= Rocket thrust
{title2=$T=u(-\dot M)$}
<Rocket thrust> is the propulsive <force> associated with ejecting <rocket propellant>. In the ideal <rocket equation> with no <pressure> correction, $T=u(-\dot M)$, where $\dot M=dM/dt<0$ is the signed rate of change of rocket <mass> and $-\dot M$ is the positive <mass loss rate>. For $u=2000\,\mathrm{m/s}$ and $\dot M=-5\,\mathrm{kg/s}$, $T=10000\,\mathrm N$. With no other <force>, the <acceleration> is $T/M$: initially $10\,\mathrm{m/s^2}$ for $M=1000\,\mathrm{kg}$, rising as <mass> falls if this <rocket thrust> stays constant.
A real exhaust outlet can also contribute a <pressure> term: $T=u(-\dot M)+A_e(p_e-p_a)$, with exit <area> $A_e$, exit <pressure> $p_e$ and ambient <pressure> $p_a$. The ideal formula here assumes that term vanishes; it must not silently absorb this correction while still interpreting $u$ as the actual relative <rocket exhaust speed>. https://www1.grc.nasa.gov/beginners-guide-to-aeronautics/rocket-thrust/[NASA Glenn Research Center: Rocket Thrust and its pressure correction]{ref}
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