Two bodies of masses m and $2m$ have same momentum. Their respective kinetic energies ${E_1}$ and ${E_2}$ are in the ratio
$1:2$
$2:1$
$1:\sqrt 2 $
$1:4$
Equal force $F ( > mg)$ is applied to string in all the $3$ cases. Starting from rest, the point of application of force moves a distance of $2 m$ down in all cases. In which case the block has maximum kinetic energy?
A ball of mass $2\;kg$ and another of mass $4\; kg$ are dropped together from a $60$ feet tall building. After a fall of $30$ feet each towards earth, their respective kinetic energies will be in the ratio of?
The kinetic energy of a body of mass $2 kg $ and momentum of $2 Ns$ is ............. $\mathrm{J}$
A block moving horizontally on a smooth surface with a speed of $40\, {ms}^{-1}$ splits into two equal parts. If one of the parts moves at $60\, {ms}^{-1}$ in the same direction, then the fractional change in the kinetic energy will be $x: 4$ where $x=..... .$
The bob of a simple pendulum (mass m and length $ l$) dropped from a horizontal position strikes a block of the same mass elastically placed on a horizontal frictionless table. The K.E. of the block will be