The kinetic energy of a body of mass $4 \,kg$ and momentum $6 \,Ns$ will be (in $\,J$)

$A$ ball of mass $2\,kg$ and another of mass $4\,kg$ are dropped together from a $60\,ft$ tall building. After a fall of $30\,ft$ each towards the earth,their respective kinetic energies will be in the ratio of:

The work done by a force on a body of mass $5 \,kg$ to accelerate it in the direction of the force from rest to $20 \,m/s$ in $10 \,s$ is:

Two masses of $1 \,g$ and $4 \,g$ are moving with equal kinetic energies. The ratio of the magnitudes of their linear momenta is

In the Olympic games,an athlete covers a distance of $100 \ m$ in $10 \ s$. The estimated range of their kinetic energy is:

Give an important factor to control the speed of a vehicle in the area of a school or hospital.