Work done in time $t$ on a body of mass $m$ which is accelerated from rest to a speed $v$ in time $t_1$ as a function of time $t$ is given by

$A$ force $\vec{F} = 2\hat{i} + b\hat{j} + \hat{k}$ is applied on a particle and it undergoes a displacement $\vec{S} = \hat{i} - 2\hat{j} - \hat{k}$. What will be the value of $b$,if the work done on the particle is zero?

The work done against gravity in taking a $10 \, kg$ mass to a $1 \, m$ height in $1 \, s$ will be .... $J$.

$A$ body of mass $10\, kg$ is dropped to the ground from a height of $10\, m$. The work done by the gravitational force is ............. $J$ $(g = 9.8\, m/s^2)$.

$A$ $1\text{ kg}$ 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 carries a load on his head through a distance of $5 \,m$. The maximum amount of work is done when he ..........