When a seagull picks an oyster up into the sky and then lets it drop on the rocks below to open the shell; where is the oyster's potential energy greatest? Where is its kinetic energy greatest?
Potential energy is greatest at maximum height; kinetic energy is greatest just before the oyster strikes the ground.
The geosphere interacts with the hydrosphere when water causes rock to erode. The atmosphere provides the geosphere with heat and energy for erosion, and the geosphere reflects the sun's energy back into the atmosphere.