A particle moves in one dimension from rest under the influence of a force that varies with the distance traveled by the particle as shown in the figure. The kinetic energy of the particle after it has traveled $3\, m$ is ................ $\mathrm{J}$

A bullet of mass $20 \,g$ leaves a riffle at an initial speed $100 \,m / s$ and strikes a target at the same level with speed $50 \,m / s$. The amount of work done by the resistance of air will be ......... $J$

A small box resting on one edge of the table is struck in such a way that it slides upto the other edge, $1 \,m$ away after $2 \,s$. The coefficient of kinetic friction between the box and the table

As shown in the figure, a particle of mass $10$ $kg$ is placed at a point $A$. When the particle is slightly displaced to its right, it starts moving and reaches the point $B$. The speed of the particle at $B$ is $x\, m / s$. (Take $\left. g =10\, m / s ^{2}\right)$ The value of $'x'$ to the nearest integer is.........

The potential energy of a particle oscillating along $x-$ axis  is given as $U = 20 + (x - 2)^2$  where $U$  is in joules and $x$ in $meters$ . Total mechanical energy of the particle is $36\,\, J$ . Maximum kinetic energy of the particle is ................ $\mathrm{J}$

How much energy produced in burning of $1\, kg$ coal ?