A man is standing on a plank which is placed on a smooth horizontal surface. There is sufficient friction between the feet of man and plank. Now man starts running over the plank. The correct statements is/are

A block is suspended from a spring at natural length and is free to move vertically in the $y$-direction. Then

The coefficient of friction between the block and plank is $\mu$ and its value is such that the block becomes stationary with respect to the plank before it reaches the other end. Then:

The correct option(s) is/are

[where $x=$compression]

Two blocks, of masses $M$ and $2M$, are connected to a light spring of spring constant $K$ that has one end fixed, as shown in figure. The horizontal surface and the pulley are frictionless. The blocks are released from rest when the spring is undeformed. The string is light. Select the correct statement(s).

The given plot shows the variation of $U$, the potential energy of interaction between two particles with the distance separating them, $r$. Then which of the following statement(s) is/are correct?

In the figure the variation of potential energy of a particle of mass $m=2 \mathrm{kg}$ is represented with respect to its $x-$coordinate. The particle moves under the effect of this conservative force along the x-axis. Which of the following statement(s) is/are correct about the particle?