$A$ force of $(3\,\hat i + 4\,\hat j) \, N$ acts on a body and displaces it by $(3\,\hat i + 4\,\hat j) \, m$. The work done by the force is .............. $J$.

$A$ force $\vec{F} = (5 \hat{\imath} - 2 \hat{\jmath} + 3 \hat{k}) \text{ N}$ acts on a body of mass $2 \text{ kg}$ and displaces it from position $\vec{r_1} = (3 \hat{\imath} + 2 \hat{\jmath} - \hat{k}) \text{ m}$ to $\vec{r_2} = (6 \hat{\imath} - \hat{\jmath} + 4 \hat{k}) \text{ m}$. The work done is: (in $\text{ J}$)

$A$ force of $5 \ N$ is required to maintain a constant velocity of $2 \ m/s$ for a block of mass $10 \ kg$ on a rough surface. The work done by this force in $1 \ minute$ is: (in $J$)

The kinetic energy acquired by a body of mass $M$ in travelling a certain distance $d$,starting from rest,under the action of a constant force is:

$A$ block of mass $m$ is kept in an elevator which starts moving downward with an acceleration $a$ as shown in the figure. The block is observed by two observers $A$ and $B$ for a time interval $t_0$. The observer $B$ (who is on the ground) finds that the work done by gravity on the block is:

$A$ force $\overrightarrow{F} = 6\hat{i} + 2\hat{j} - 3\hat{k}$ acts on a particle and produces a displacement of $\overrightarrow{s} = 2\hat{i} - 3\hat{j} + x\hat{k}$. If the work done is zero,the value of $x$ is