The force constant of a weightless spring is $16 \,N/m$. A body of mass $1.0\, kg$ suspended from it is pulled down through $5\, cm$ and then released. The maximum kinetic energy of the system (spring + body) will be
$2 \times {10^{ - 2}}\,J$
$4 \times {10^{ - 2}}\,J$
$8 \times {10^{ - 2}}\,J$
$16 \times {10^{ - 2}}\,J$
A wooden block of mass $M$ is suspended by a cord and is at rest. A bullet of mass $m,$ moving with a velocity $v$ passes through the block and comes out with a velocity $v/2$ in the same direction. If there is no loss in kinetic energy, then upto what height the block will rise
A projectile is fired with $KE$ of $1\,kJ$. If the range is maximum, .......... $J$ is its $KE$ at the highest point.
Two bodies of masses $2m$ and $m$ have their K.E. in the ratio $8 : 1$, then their ratio of momenta is
A bullet moving with a speed of $100$ $m{s^{ - 1}}$can just penetrate two planks of equal thickness. Then the number of such planks penetrated by the same bullet when the speed is doubled will be
A running man has half the kinetic energy of that of a boy of half of his mass. The man speeds up by $1\,m/s$ so as to have same K.E. as that of the boy. The original speed of the man will be