A rocket has an initial mass of $150 \mathrm{~kg}$. After operating for a duration of $10 \mathrm{~s}$, its final mass is $50 \mathrm{~kg}$. If the acceleration due to gravity is $9.81 \mathrm{~m} / \mathrm{s}^{2}$ and the thrust produced by the rocket is $19.62 \mathrm{kN}$, the specific impulse of the rocket is
(A) $400 \mathrm{~s}$
(B) $300 \mathrm{~s}$
(C) $200 \mathrm{~s}$
(D) $100 \mathrm{~s}$
A rocket has an initial mass of $150 \mathrm{~kg}$. After operating for a duration of $10 \mathrm{~s}$, its final mass is $50 \mathrm{~kg}$. If the acceleration due to gravity is $9.81 \mathrm{~m} / \mathrm{s}^{2}$ and the thrust produced by the rocket is $19.62 \mathrm{kN}$, the specific impulse of the rocket is
(A) $400 \mathrm{~s}$
(B) $300 \mathrm{~s}$
(C) $200 \mathrm{~s}$
(D) $100 \mathrm{~s}$