Burnout Height of Upward Rocket under Constant Gravity
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Theorem
Let $R$ be a rocket whose structural mass is $m_1$.
Let $R$ contain fuel of initial mass $m_2$.
Let $R$ be fired straight up from the surface of a planet whose gravitational field exerts an Acceleration Due to Gravity of $g$, assumed constant.
Let $R$ burn fuel at a constant rate $a$, with a constant exhaust velocity $b$ relative to $R$.
Let all forces on $R$ except that due to the gravitational field be neglected.
Then the burnout height of $R$ is given by:
- $h_b = -\dfrac {g m_2^2} {2 a^2} + \dfrac {b m_2} a + \dfrac {b m_1} a \ln \dfrac {m_1} {m_1 + m_2}$
Proof
Sources
- 1972: George F. Simmons: Differential Equations ... (previous) ... (next): Miscellaneous Problems for Chapter $2$: Problem $29$