Question

where is the energy of the roller coaster cart entirely potential? when it moves up the hill at location a when it is traveling down the hill at location c when it stops for a brief moment at location b

Explanation:

Potential energy in a roller - coaster system is related to height and mass. When the cart stops briefly, its kinetic energy is zero (as velocity is zero), and if it is at a high - point, all of its mechanical energy is potential. At location B, when it stops briefly, it has maximum height among the given scenarios and no motion (zero kinetic energy), so all energy is potential.

Answer:

When it stops for a brief moment at location B