$A$ block of mass $m$ is hung vertically from an elastic thread of force constant $mg/a$. Initially the thread was at its natural length and the block is allowed to fall freely. The kinetic energy of the block when it passes through the equilibrium position will be :
$mga$
$mga/2$
zero
$2mga$
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
Sand is deposited at a uniform rate of $20\ kg/s$ and with negligible kinetic energy on an empty conveyor belt moving horizontally at a constant speed of $10$ meters per minute. Find the force required to maintain constant velocity of the conveyor belt.
Two masses of $1\,kg$ and $16\,kg$ are moving with equal K.E. The ratio of magnitude of the linear momentum is
A rifle bullet loses $1/20^{th}$ of its velocity in passing through a wooden plank. The least number of planks required to stop the bullet is :-
Two bodies are having kinetic energies in the ratio $16: 9$. If they have same linear momentum, the ratio of their masses respectively is