An object of mass $3\,kg$ is at rest. If a force $\vec{F} = (6t^2\hat{i} + 4t\hat{j})\,N$ is applied on the object,then the velocity of the object at $t = 3\,s$ will be

$A$ 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?

$A$ body of mass $2 \, kg$ is moving with a velocity $8 \, m/s$ on a smooth surface. If it is to be brought to rest in $4 \, seconds$,then the force to be applied is ......... $N$.

$A$ vehicle of $100\, kg$ is moving with a velocity of $5\, m/s$. To stop it in $\frac{1}{10}\, s$,the required force in the opposite direction is ........... $N$.

$A$ car of mass $1500 \,kg$ is moving with $20 \,ms^{-1}$ velocity. If the brakes are applied,it comes to rest in $5 \,s$. The retarding force is: (in $\,N$)

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 $20 \ N$?