Which of the following graphs represent kinetic energy $\left(K\right),$ potential energy $\left(U\right)$ and height $\left(h\right)$ from the ground for a freely falling body?

Two springs of force constants $k_1$ and $k_2$ are stretched by the same force. The ratio of potential energies stored in them is

In the figure, mass of $A$ is $m$ and that of $B$ is $2\mathrm{m}$. All the surface are smooth. System is released from rest with spring unstretched. Then, the maximum extension $X_m$ in spring will be