Two particles of the same mass are moving in circular orbits because of force, given by $F(r) = \frac{{ - 16}}{r}\, - \,{r^3}$ The first particle is at a distance $r = 1,$ and the second, at $r = 4.$ The best estimate for the ratio of kinetic energies of the first and the second particle is closest to
$10^{-1}$
$6 \times {10^{-2}}$
$6 \times {10^2}$
$3 \times {10^{-3}}$
The slope of kinetic energy displacement curve of a particle in motion is
A wooden block of mass $M$ is suspended by a cord and is at rest. A bullet of mass $m,$ moving with a velocity $v$ passes through the block and comes out with a velocity $v/2$ in the same direction. If there is no loss in kinetic energy, then upto what height the block will rise
A bomb of mass $9\,kg$ explodes into $2$ pieces of mass $3\,kg$ and $6\,kg.$ The velocity of mass $3\,kg$ is $1.6\, m/s$, the K.E. of mass $6\,kg$ is ............ $J$
A block moving horizontally on a smooth surface with a speed of $40\, {m} / {s}$ splits into two parts with masses in the ratio of $1: 2$. If the smaller part moves at $60\, {m} / {s}$ in the same direction, then the fractional change in kinetic energy is :-
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