The graph of resistive force versus displacement for an object of mass $25 \ kg$ is given. If its velocity at $x = 0$ is $2 \ m/s$,then its kinetic energy at $x = 4 \ m$ is ..... $J$.

Power applied to a particle varies with time as $P = (4t^3 - 5t + 2) \, W$,where $t$ is in seconds. Find the change in its $K.E.$ between time $t = 2 \, s$ and $t = 4 \, s$. ............... $J$

The value of the force constant for the given force-displacement graph is:

$A$ body of mass $3\, kg$ is under a force,which causes a displacement given by $S = \frac{t^3}{3}$ (in $m$). Find the work done by the force in the first $2\, s$.

$A$ block of mass $1 \ kg$,moving along the $x$-axis with an initial speed $v_{i} = 10 \ m/s$,enters a rough region ranging from $x = 0.1 \ m$ to $x = 1.9 \ m$. The retarding force acting on the block in this range is $F_{r} = -kx \ N$,where $k = 10 \ N/m$. Find the final speed of the block as it crosses the rough region.

The relationship between force $F$ and displacement $x$ is shown in the figure. The work done by the object for a displacement from $x = 1 \ m$ to $x = 5 \ m$ is equal to ... $J$.