$A$ particle gets displaced by $\Delta \vec{r} = (2\hat{i} + 3\hat{j} + 4\hat{k}) \text{ m}$ under the action of a force $\vec{F} = (7\hat{i} + 4\hat{j} + 3\hat{k}) \text{ N}$. The change in its kinetic energy is ............... $\text{J}$.

Explain work done by a constant force.

Two constant forces ${F_1} = 2\hat i - 3\hat j + 3\hat k$ $(N)$ and ${F_2} = \hat i + \hat j - 2\hat k$ $(N)$ act on a body and displace it from the position ${r_1} = \hat i + 2\hat j - 2\hat k$ $(m)$ to the position ${r_2} = 7\hat i + 10\hat j + 5\hat k$ $(m)$. What is the work done in $J$?

$A$ boy holds a uniform chain of length $2 \, m$ which is kept on a smooth table such that a length of $60 \, cm$ hangs freely from the edge of the table. The total mass of the chain is $4 \, kg$. What is the work done in pulling the entire chain on the table (in $, J$)? (Take $g = 10 \, m/s^2$)

In the figure shown,all the surfaces are frictionless,and the mass of the block $m$ is $1\,kg$. The block and wedge are held initially at rest. Now,the wedge is given a horizontal acceleration of $5\,m/s^2$ by applying a force on the wedge,such that the block does not slip on the wedge. Then,the work done by the normal force in the ground frame on the block in $2\,sec$ is ............... $J$.

$A$ ship of mass $3 \times 10^7 \, kg$ initially at rest is pulled by a force of $5 \times 10^4 \, N$ through a distance of $3 \, m$. Assuming that the resistance due to water is negligible,the speed of the ship is ........... $m/s$.