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

$A$ constant force acting on a body of mass $3.0 \, kg$ changes its speed from $2.0 \, m/s$ to $3.5 \, m/s$ in $25 \, s$. The direction of the motion of the body remains unchanged. What is the magnitude and direction of the force?

$A$ particle of mass $m$ is moving in a straight line with momentum $p$. Starting at time $t = 0$,a force $F = kt$ acts in the same direction on the moving particle during time interval $T$ so that its momentum changes from $p$ to $3p$. Here $k$ is a constant. The value of $T$ is

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

$A$ body of mass $500\,g$ moves along the $x$-axis such that its velocity varies with displacement $x$ according to the relation $v = 10\sqrt{x}\,m/s$. The force acting on the body is $...........\,N$.

$A$ particle of mass $2/3 \, kg$ with velocity $v = -15 \, m/s$ at $t = -2 \, s$ is acted upon by a force $F = k - \beta t^2$. Here,$k = 8 \, N$ and $\beta = 2 \, N/s^2$. The motion is one-dimensional. Then,the speed at which the particle acceleration is zero again,is ........... $m/s$.