A rocket, with a total lift-off mass of $10000 \mathrm{~kg}$, moves vertically upward from rest under a constant gravitational acceleration of $9.81 \mathrm{~m} / \mathrm{s}^{2}$. The propellant mass of $8400 \mathrm{~kg}$ burns at a constant rate of $1200 \mathrm{~kg} / \mathrm{s}$. If the specific impulse of the rocket engine is $240 \mathrm{~s}$, neglecting drag, the burnout velocity in $\mathrm{m} / \mathrm{s}$ is
(A) 3933.7
(B) 4314.6
(C) 4245.9
(D) 4383.3
A rocket, with a total lift-off mass of $10000 \mathrm{~kg}$, moves vertically upward from rest under a constant gravitational acceleration of $9.81 \mathrm{~m} / \mathrm{s}^{2}$. The propellant mass of $8400 \mathrm{~kg}$ burns at a constant rate of $1200 \mathrm{~kg} / \mathrm{s}$. If the specific impulse of the rocket engine is $240 \mathrm{~s}$, neglecting drag, the burnout velocity in $\mathrm{m} / \mathrm{s}$ is
(A) 3933.7
(B) 4314.6
(C) 4245.9
(D) 4383.3