If the kinetic energy of an object becomes four times its initial value,what will be its new momentum?

$A$ particle is released freely from a height $H$. At a certain height,its kinetic energy is two times its potential energy. Then,the height and the speed of the particle at that instant are respectively ($g=$ acceleration due to gravity).

When the mass and speed of the body are doubled,the kinetic energy of the body

$A$ particle of mass $m_1$ moves with velocity $v_1$ and another particle of mass $m_2$ moves with velocity $v_2$. Both have the same momentum,but their kinetic energies are $E_1$ and $E_2$ respectively. If $m_1 > m_2$,then:

The graph between kinetic energy $E$ and velocity $v$ is:

$A$ running man has half the kinetic energy of a boy who has half the man's mass. The man speeds up by $1 \, m/s$ so that his kinetic energy becomes equal to that of the boy. The original speed of the man is: