The kinetic energy acquired by a body of mass $m$ traveling a distance $s$,starting from rest under the action of a constant force,is directly proportional to:

$A$ block of mass $m$ is kept in an elevator which starts moving downward with an acceleration $a$ as shown in the figure. The block is observed by two observers $A$ and $B$ for a time interval $t_0$. According to observer $B$,the net work done on the block is

$A$ uniform rope of length $4 \,m$ and mass $0.4 \,kg$ is held on a frictionless table in such a way that $0.6 \,m$ of the rope is hanging over the edge. The work done to pull the hanging part of the rope onto the table is, (Assume $g = 10 \,m/s^2$) (in $\,J$)

$A$ particle of mass $100 \ g$ is projected vertically upwards with a speed of $5 \ m/s$. What is the work done by the force of gravity during the time the particle returns to the starting point? (in $J$)

$A$ force of $5 \, N$ acts on a $15 \, kg$ body initially at rest. The work done by the force during the first second of motion of the body is

How much work does a pulling force of $40\, N$ do on a $20\, kg$ box in pulling it $8\, m$ across a smooth floor at a constant speed? The pulling force is directed at $60^{\circ}$ above the horizontal. (Answer in $J$)