A particle falls from rest under gravity. Its potential energy $\left(PE\right)$ with respect to ground and its kinetic energy $\left(KE\right)$ are plotted with time $t$. Choose the correct graph.

Consider the spring block system shown in the figure initially block $m$ is in equilibrium. An impulse gives the block a velocity $v$ upwards. Find the maximum speed of the block during the motion.

A block of mass $m$ is released from a height $h$ from the top of a smooth surface. There is an ideal spring of spring constant $k$ at the bottom of the track. Find the maximum compression in the spring. (Wedge is fixed)