$A$ chain of length $L$ and mass $M$ is placed on a frictionless table with one-fifth of its length hanging over the edge. What is the work required to pull the hanging part back onto the table?

The following figure shows the variation of potential energy $V(x)$ of a particle with distance $x$. The particle has

If a stone is thrown vertically upward and returns to the ground,its potential energy is maximum:

If the potential energy of a particle is given by $U = A - Bx^2$,then the force is proportional to which of the following?

$A$ particle is constrained to move along the $x$-axis. $A$ force is applied to it in the same direction,which varies with the distance $x$ from the origin as $F(x) = -kx + ax^3$,where $k$ and $a$ are positive constants. What will be the graph of the potential energy $U(x)$ of the particle for $x \ge 0$?

Potential energy is a......