$A$ spring is stretched by $0.40 \ m$ when a mass of $0.6 \ kg$ is suspended from it. The period of oscillations of the spring loaded by $255 \ g$ and put to oscillations is close to $(g = 10 \ m \ s^{-2})$. (in $s$)

$A$ block of mass $m$,attached to a spring of spring constant $k$,oscillates on a smooth horizontal table. The other end of the spring is fixed to a wall. The block has a speed $v$ when the spring is at its natural length. Before coming to an instantaneous rest,if the block moves a distance $x$ from the mean position,then

On a smooth inclined plane,a body of mass $M$ is attached between two springs. The other ends of the springs are fixed to firm supports. If each spring has a force constant $K$,the period of oscillation of the body (assuming the springs are massless) is

The variation of potential energy of a harmonic oscillator is as shown in the figure. The spring constant is

The effective spring constant of the two-spring system as shown in the figure will be:

$A$ $3 \ kg$ block is connected as shown in the figure. The spring constants of the two springs $K_1$ and $K_2$ are $50 \ Nm^{-1}$ and $150 \ Nm^{-1}$ respectively. The block is released from rest with the springs unstretched. The acceleration of the block in its lowest position is $(g=10 \ ms^{-2})$. (in $ms^{-2}$)