Question

A rocket of initial mass 6000 kg ejects gases at a constant rate of $16kgs^{- 1}$with constant relative speed of $11kgs^{- 1}$.What6 is the acceleration of the rocket one minute after the blast?

• A. $25ms^{- 2}$
• B. $50ms^{- 2}$
• C. $10ms^{- 2}$
• D. $35ms^{- 2}$

Answer 1

Answer: (D)

$35ms^{- 2}$

Answer 2

Acceleration of the rocket at any instant t is

$a = \frac{v_{r}\frac{dm}{dt}}{M - t\frac{dm}{dt}}$

Here, $M = 6000kg,\frac{dm}{dt} = 16kgs^{- 1}$

}{t = 1\min = 60s }{\therefore a = \left\lbrack \frac{11000 \times 16}{6000 - 60 \times 16} \right\rbrack ms^{- 2} \approx 35ms^{- 2}}$$