What is the mass of an object whose weight is $1\,N$ (in $,kg$)?

The velocity of an object of mass $2 \ kg$ is given by $v = (8t \hat{i} + 3t^2 \hat{j}) \ m/s$, where $t$ is time in seconds. What will be the direction of the net force on the object relative to the positive direction of the $X$-axis, at the instant when its magnitude is $20 \ N$?

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 ......... $N$.

$A$ cricket ball of mass $50 \ g$ having velocity $50 \ cm \ s^{-1}$ is stopped in $0.5 \ s$. The force applied to stop the ball is (in $N$)

$A$ cricketer catches a ball of mass $150\; g$ in $0.1\; s$ moving with a speed of $20\; m/s$. The force experienced by the cricketer is ..... $N$.

$A$ particle of mass $m$ is at rest at the origin at time $t = 0$. It is subjected to a force $F(t) = F_0e^{-bt}$ in the $x$ direction. Its speed $v(t)$ is depicted by which of the following curves?