Question

In case of rocket propulsion choose the correct options.

• A. Momentum of rocket always remains constant.
• B. Newton's third law is applied.
• C. If exhaust velocity and rate of burning of mass is kept constant, then acceleration of rocket will go on increasing.
• D. If exhaust velocity and rate of burning of mass is kept constant, then thrust force will be constant

Answer 1

Answer: (B), (C), (D)

Newton's third law is applied.
If exhaust velocity and rate of burning of mass is kept constant, then acceleration of rocket will go on increasing.
If exhaust velocity and rate of burning of mass is kept constant, then thrust force will be constant

Newton's Second law$\Rightarrow F=ma$
Newton's Third law$\Rightarrow$ Every action has an equal and opposite reaction.
External force gravity acts on system. Therefore momentum of system is not conserved.
Mass keep on decreasing. Therefore acceleration will keep on increasing.