The potential energy is most often referred to as the "energy at rest" and is dependent on the elevation of an object. This can be calculated through the equation,
E = mgh
where E is the potential energy, m is the mass, g is the acceleration due to gravity, and h is the height. In this item, we are not given with the mass of the cart so we assume it to be m. The force is therefore,
E = m(9.8 m/s²)(0.5 m) = 4.9m
Hence, the potential energy is equal to 4.9m.
The system of two rods will lie on the table as show in the figure
The center of first rod will lie exactly at the edge of first rod and then the center of mass of two combined rods will lie at the edge of the table.
So now the whole system will rest on the rod and it will not tipping off.
Since both rods are identical so we can say that the system will have its center of mass at the mid point on the line joining the two centers
So the value of x will be at mid point of line joining the two points on rod

So total length over the edge will be given as
