A bullet of mass $0.1\,kg$ is fired with a speed of $100\, m/sec$, the mass of gun is $50\, kg$. The velocity of recoil is ........ $m/sec$
$0.2$
$0.1$
$0.5 $
$0.05 $
The motion of a rocket is based on the principle of conservation of
A body of mass $1000 \mathrm{~kg}$ is moving horizontally with a velocity $6 \mathrm{~m} / \mathrm{s}$. If $200 \mathrm{~kg}$ extra mass is added, the final velocity (in $\mathrm{m} / \mathrm{s}$ ) is:
A body of mass $5 \,kg$ explodes at rest into three fragments with masses in the ratio $1 : 1 : 3$. The fragments with equal masses fly in mutually perpendicular directions with speeds of $21 \,m/s$. The velocity of the heaviest fragment will be
Three particles of masses $10\;g, 20\;g$ and $40\;g$ are moving with velocities $10\widehat i,10\widehat j$ and $10\widehat k\;m/s$ respectively. If due to some mutual interaction, the first particle comes to rest and the velocity of second particle becomes $\left( {3\widehat i + 4\widehat j\,\,} \right)\, m/s$, then the velocity of third particle is
Rocket engines lift a rocket from the earth surface because hot gas with high velocity