Two bodies of masses $2m$ and $m$ have their K.E. in the ratio $8 : 1$, then their ratio of momenta is
$1:1$
$2:1$
$4:1$
$8:1$
A bomb is kept stationary at a point. It suddenly explodes into two fragments of masses $1\, g$ and $3\;g$. The total K.E. of the fragments is $6.4 \times {10^4}J$. What is the K.E. of the smaller fragment
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 bullet of mass $50 \mathrm{~g}$ is fired with a speed $100 \mathrm{~m} / \mathrm{s}$ on a plywood and emerges with $40 \mathrm{~m} / \mathrm{s}$. The percentage loss of kinetic energy is :
A spherical body of mass $2\,kg$ starting from rest acquires a kinetic energy of $10000\,J$ at the end of $5^{\text {th }}$ second. The force acted on the body is $.....N$
A particle of mass $'m'$ and charge $'q'$ is accelerated through a potential difference of $'V'$ volt. Its energy is