A $50\,kg$ man with $20\,kg$ load on his head climbs up $20$ steps of $0.25\,m$ height each. The work done in climbing is......$J$

A particle of mass $0.1 \,kg$ is subjected to a force which varies with distance as shown. If it starts its journey from rest at $x=0$, then its velocity at $x=12 \,m$ is .............. $m / s$

An athlete in the olympic games covers a distance of $100\ m$ in $10\ s$. His kinetic energy can be estimated to be in the range

Masses of two substances are $1\, g$ and $9\, g$ respectively. If their kinetic energies are same, then the ratio of their momentum will be

If the kinetic energy of body increases them ?

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 :-