$A$ body of mass $8 \ kg$,under the action of a force,is displaced according to the equation $s = \frac{t^2}{4} \ m$,where '$t$' is the time. Find the work done by the force in the first $4 \ s$. (in $J$)

$A$ body moves a distance of $10 \ m$ along a straight line under the action of a force of $5 \ N$. If the work done in this process is $25 \ J$,what is the angle between the force and the displacement in degrees?

$A$ body,acted upon by a force of $50 \, N$,is displaced through a distance of $10 \, m$ in a direction making an angle of $60^\circ$ with the force. The work done by the force is .......... $J$.

$A$ man starts walking from a point on the surface of the Earth (assumed smooth) and reaches the diagonally opposite point. What is the work done by him?

When a particle moves from its origin to a point with position vector $\vec{r} = (2\hat{i} - \hat{j}) \ m$,it is subjected to a force $\vec{F} = (5\hat{i} + 3\hat{j} + 2\hat{k}) \ N$. What is the work done by the force in Joules?

$A$ force $\vec F = (5\hat i + 3\hat j) \ N$ is applied to a particle,which displaces it from its original position to the point $\vec s = (2\hat i - 1\hat j) \ m$. The work done on the particle is ......... $J$.