Newton's second law gives the measure of

$A$ force $(2 \hat{i} + \hat{j} - \hat{k}) \text{ N}$ acts on a body, which is initially at rest. At the end of $20 \text{ s}$, the velocity of the body is $(4 \hat{i} + 2 \hat{j} - 2 \hat{k}) \text{ ms}^{-1}$. The mass of the body is: (in $\text{ kg}$)

$A$ boy pushes a box of mass $2 \, kg$ with a force $\overrightarrow{F} = (20 \hat{i} + 10 \hat{j}) \, N$ on a frictionless surface. If the box was initially at rest,then the displacement along the $x$-axis after $10 \, s$ is ........... $m$.

$A$ constant force $F$ acts on two different masses $m_1$ and $m_2$ independently and produces accelerations $A_1$ and $A_2$ respectively. When the same force $F$ acts on their combined mass $(m_1 + m_2)$,the acceleration $A$ produced is:

$A$ 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,under the action of a force $\vec F = 6\hat i - 8\hat j + 10\hat k$,acquires an acceleration of $1\, m/s^2$. The mass of this body must be