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

$A$ man carries a bucket of weight $60 \ N$ and walks $7 \ m$ in the horizontal direction,then climbs $5 \ m$ in the vertical direction. What is the work done by the man in $J$?

$A$ 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?

$A$ particle of mass $m$ moves along a circular path of radius $r$ under the influence of a centripetal force $F$. What is the work done when the particle moves along a semi-circular path?

$A$ body of mass $5\, kg$ is placed at the origin and can move only on the $x$-axis. $A$ force of $10\, N$ is acting on it in a direction making an angle of $60^\circ$ with the $x$-axis and displaces it along the $x$-axis by $4\, m$. The work done by the force is $...\, J$.

The force $F$ acting on a body moving in a circle of radius $r$ is always perpendicular to the instantaneous velocity $v$. The work done by the force on the body in one complete rotation is: