The energy of the roller coaster at the bottom of the loop is given as
E = 658 J.
This is the kinetic energy of the roller coaster.
Due to this kinetic energy, the roller coaster starts moving upwards.
With the increasing height of the roller coaster, potential energy increases and kinetic energy decreases.
Thus, at the top of the loop, the roller coaster has only potential energy.
According to the conservation of energy,
![\begin{gathered} \text{Energy at the bottom of the loop = Energy at the top of the loop} \\ E=\text{ 658 J} \end{gathered}]()
Thus, the answer is 658 J.