Sand is being dropped on a conveyor belt at the rate of $M \ kg/s$. The force necessary to keep the belt moving with a constant velocity of $v \ m/s$ will be

Consider a rocket is being fired. The kinetic energy of the rocket is increased by $16$ times, whereas its total mass is reduced by half through the burning of fuel. The factor by which its momentum increases is

$A$ rocket with a lift-off mass of $3.5 \times 10^4 \ kg$ is blasted upwards with an initial acceleration of $10 \ m/s^2$. The initial thrust of the blast is:

$A$ rocket which has a mass of $3.5 \times 10^4 \,kg$ is blasted upwards with an initial acceleration of $10 \,m/s^2$. The initial thrust of the blast is-

$A$ rocket has an initial mass of $20 \times 10^3 \, kg$. If it is to blast off with an initial acceleration of $4 \, m/s^2$,the initial thrust needed is $(g = 10 \, m/s^2)$.

$A$ balloon has a mass of $10\,g$ in air. The air escapes from the balloon at a uniform rate with a velocity of $4.5\,cm/s$. If the balloon shrinks completely in $5\,s$,then the average force acting on the balloon will be (in $dyne$).