$A$ man carries a load on his head through a distance of $5 \,m$. The maximum amount of work is done when he ..........

The kinetic energy $K$ of a particle moving in a straight line depends upon the distance $s$ as $K = as^2$. The force acting on the particle is

$A$ body of mass $m$ starts from rest and acquires a velocity $v$ in time $t_1$. The work done in time $t$ is proportional to:

$A$ $1\text{ kg}$ block subjected to two simultaneous forces $\vec{F}_1 = (2\hat{i} + 3\hat{j} + 4\hat{k})\text{ N}$ and $\vec{F}_2 = (3\hat{i} - \hat{j} - 2\hat{k})\text{ N}$ is moved a distance of $25\text{ m}$ along the $(3\hat{i} - 4\hat{j})$ direction. The work done in this process is . . . . . . $J$.

$A$ man of mass $50 \ kg$ carrying a load of $10 \ kg$ reaches the top of a building in $4 \ minutes$. The work done by the man is $6 \times 10^4 \ J$. If he reaches the top in $2 \ minutes$,the work done by the man will be:

$A$ force $\vec{F} = 6\hat{i} + 2\hat{j} - 3\hat{k}$ acts on a particle,causing a displacement $\vec{S} = 2\hat{i} - 3\hat{j} + x\hat{k}$. If the work done during this displacement is zero,find the value of $x$.