When a body is acted upon by a constant force,then which of the following quantities remains constant?

Which physical quantity is represented by the first derivative of linear momentum with respect to time?

The momentum $p$ (in $kg \cdot m/s$) of a particle is varying with time $t$ (in $s$) as $p = 2 + 3t^2$. The force acting on the particle at $t = 3 \, s$ will be ......... $N$.

An object with a mass of $10\, kg$ moves at a constant velocity of $10\, m/s$. $A$ constant force then acts for $4\, s$ on the object and gives it a speed of $2\, m/s$ in the opposite direction. The force acting on the object is ......... $N$.

$A$ particle of mass $M$ originally at rest is subjected to a force whose direction is constant but magnitude varies with time according to the relation $F = F_{0} \left(1 - \left(\frac{t - T}{T}\right)^{2}\right)$. Where $F_{0}$ and $T$ are constants. The force acts only for the time interval $2T$. The velocity $v$ of the particle after time $2T$ is:

$A$ person holds a ball of mass $0.25 \ kg$ in his hand and throws it,so that it leaves his hand with a speed of $12 \ m \ s^{-1}$. In this process,if his hand moved through a distance of $0.9 \ m$,then the net force acted on the ball is (in $N$)