$A$ sphere of mass $25 \,g$ is placed on a vertical spring. The spring is compressed by $0.2 \,m$ using a force of $5 \,N$. When the spring is released, the mass reaches a maximum height of (take $g = 10 \,m/s^2$):

One end of a spring of spring constant $80 \ Nm^{-1}$ and unstretched length of $30 \ cm$ is fixed at point $A$ and the other end of the spring is fitted with a smooth ring of mass $300 \ g$ as shown in the figure. The ring is allowed to slide on a horizontal rod fixed at a height of $40 \ cm$. Initially the spring makes an angle of $60^{\circ}$ with the vertical and the system of spring and ring is released from rest. The speed of the ring when the spring becomes vertical is . . . . . . $ms^{-1}$.

$A$ spring of force constant $k$ is cut into two parts at one-third of its length. When both parts are stretched by the same amount,the work done in the two parts will be:

$A$ block of mass $m$ moving at a speed $v$ compresses a spring through a distance $x$ before its speed becomes one fourth. Find the spring constant of the spring.

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 ................ $J$.

When a body of mass $m$ is attached to a vertical spring of natural length $L$ and released,the spring stretches by a distance $h$. What will be the potential energy of the stretched spring?