$A$ rocket is ejecting $50\,g$ of gases per second at a speed of $500\,m/s.$ The accelerating force on the rocket will be ............ $N$.

$A$ rocket of initial mass $1500 \ kg$ ejects gas at a constant rate of $10 \ kg/s$ with a relative speed of $5 \ km/s$. The acceleration of the rocket $50 \ s$ after the blast,neglecting gravity,is $x \ ms^{-2}$. Find the value of $x$.

$A$ $2\,kg$ chain is in the form of a heap. Its length is $2\,m$. Its one end is being pulled at a constant speed of $2\,m/s$ horizontally. The power delivered to the chain is (in $W$).

Sand is being poured at a rate of $50 \, kg/min$ into a train moving with a velocity of $20 \, m/s$. To maintain the constant velocity of the train,the force required is ........ $N$.

An open carriage in a goods train is moving with a uniform velocity of $10 \,m/s$. If the rain adds water with zero velocity at the rate of $5 \,kg/s$,then the additional force required by the engine to maintain the same velocity of the train is ....... $N$.

At a certain instant of time,the mass of a rocket going up vertically is $100 \, kg$. If it is ejecting $5 \, kg$ of gas per second at a speed of $400 \, m/s$,the acceleration of the rocket would be ........ $m/s^2$ (taking $g = 10 \, m/s^2$).