If an object in a fluid is more dense than that fluid then that object will sink in that fluid because of gravity, and waves can be created at the boundary between fluids of different densities. Given these facts, objects will sink between boundaries with different what due to gravity among the following options:
- Energy.
 - surfaces
 - densities
 - forces
 - rocks
 - minerals
 - energy
 - heat energy


 

   densities      