If the kinetic energy of a body is directly proportional to time $t,$ the magnitude of force acting on the body is
$(i)$ directly proportional to $\sqrt t$
$(ii)$ inversely proportional to $\sqrt t$
$(iii)$ directly proportional to the speed of the body
$(iv)$ inversely proportional to the speed of body
$(i),\,(ii)$
$(i),\,(iii)$
$(ii),\,(iv)$
$(i),\,(iv)$
A bullet of mass $50 \mathrm{~g}$ is fired with a speed $100 \mathrm{~m} / \mathrm{s}$ on a plywood and emerges with $40 \mathrm{~m} / \mathrm{s}$. The percentage loss of kinetic energy is :
At time $t=0$ is particle starts moving along the $x-$axis. If its kinetic energy increases uniformly with time $t$, the net force acting on it must be proportional to
A bomb of mass $30\,kg$at rest explodes into two pieces of masses $18\,kg$ and $12\,kg$. The velocity of $18\,kg$ mass is $6\,m{s^{ - 1}}$. The kinetic energy of the other mass is ....... $J$
The kinetic energy $K$ of a particle moving along $x$-axis varies with its position $(x)$ as shown in figure The magnitude of force acting on particle at $x=9 \,m$ is ............ $N$
If the momentum of a body is increased $n$ times, its kinetic energy increases