Three masses $700g, 500g$ and $400g$ are suspended at the end of a spring a shown  and are in equilibrium. When the $700g$ mass is removed, the system oscillates with a  period of $3\,seconds$, when the $500g$ mass is also removed, it will oscillate with a period of .... $s$

A mass hangs from a spring and oscillates vertically. The top end of the spring is attached to the top of a box, and the box is placed on a scale, as shown in the figure. The reading on the scale is largest when the mass is

Let $T_1$ and $T_2$ be the time periods of two springs $A$ and $B$ when a mass $m$ is suspended from them separately. Now both the springs are connected in parallel  and same mass $m$ is suspended with them. Now let $T$ be the time period in this position. Then

What will be the force constant of the spring system shown in the figure

An ideal spring with spring-constant $K$ is hung from the ceiling and a block of mass $M$ is attached to its lower end. The mass is released with the spring initially unstretched. Then the maximum extension in the spring is

A body of mass $5\; kg$ hangs from a spring and oscillates with a time period of $2\pi $ seconds. If the ball is removed, the length of the spring will decrease by