$A$ mass of $1\, kg$ is hanging from a spring of spring constant $1\, N/m$. If Saroj pulls the mass down by $2\, m$,the work done by Saroj is......$J$.

$A$ spring of force constant $K$ is first stretched by distance $a$ from its natural length and then further by distance $b$. The work done in stretching the part $b$ is .............

When an elastic spring is stretched or compressed,does its potential energy increase or decrease?

The $P.E.$ of a certain spring when stretched from natural length through a distance $0.3\, m$ is $10\, J$. The amount of work in joule that must be done on this spring to stretch it through an additional distance $0.15\, m$ will be ................ $J$.

$A$ block of mass $m$ is pushed against a spring with spring constant $k$,which is fixed at one end to a wall. The block can slide on a frictionless table as shown in the figure. If the natural length of the spring is $L_0$ and it is compressed to half its length when the block is released,find the velocity of the block when the spring reaches its natural length.

$A$ long spring, when stretched by a distance $x$, has the potential energy $u$. On increasing the stretching to $nx$, the potential energy of the spring will be: