For a mechanism shown below, the mechanical advantage for the given configuration is

The figure below shows a planar mechanism with single degree of freedom. The instant center $${{\rm I}_{24}}$$ for the given configuration is located at a position.

A vibrating machine is isolated from the floor using springs. If the ratio of excitation frequency of vibration of machine to the natural frequency of the isolation system is equal to 0.5, the transmissibility ratio of isolation is

A uniform stiff rod of length $$300$$ $$mm$$ and having a weight of $$300$$ $$N$$ is pivoted at one end and connected to a spring at the other end. For keeping the rod vertical in a stable position the minimum value of spring constant $$K$$ needed is