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?

Two identical uniform discs roll without slipping on two different surfaces $AB$ and $CD$ (see figure) starting at $A$ and $C$ with linear speeds $v _1$ and $v _2$, respectively, and always remain in contact with the surfaces. If they reach $B$ and $D$ with the same linear speed and $v_1=3 \ m / s$, then $v_2$ in $m / s$ is $\left(g=10 \ m / s ^2\right)$

When kinetic energy of a body becomes $36$ times of its original value, the percentage increase in the momentum of the body will be :

A body of mass $8\,kg$ and another of mass $2\, kg$ are moving with equal kinetic energy. The ratio of their respective momenta will be.

A bomb of $12 kg$ divides in two parts whose ratio of masses is $1 : 3$. If kinetic energy of smaller part is $216 J$, then momentum of bigger part in kg-m/sec will be

A bullet is fired from a gun. If the gun recoils freely, the kinetic energy of the gun will be