If a body of mass $200\, g$ falls from a height $200 \,m$ and its total $P.E.$ is converted into $K.E.$ at the point of contact of the body with earth surface, then what is the decrease in $P.E.$ of the body at the contact $(g = 10\,m/{s^2})$ ............ $\mathrm{J}$

If the linear momentum is increased by $5\%$, the kinetic energy will increase by.......$\%$

If a body looses half of its velocity on penetrating $3 \,cm$ in a wooden block, then how much will it penetrate more before coming to rest ........... $cm$

If the momentum of a body is increased $n$ times, its kinetic energy increases

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

An electron and a proton are detected in a cosmic ray experiment, the first with kinetic energy $10\; keV$, and the second with $100\; keV$. Which is faster, the electron or the proton? Obtain the ratio of their speeds. (electron mass $=9.11 \times 10^{31}\; kg$. proton mass $=1.67 \times 10^{-27}\;$$ kg , 1 \;eV =1.60 \times 10^{-19} \;J )$