The water in an aquarium is warmed by a heater locate under the gravel in the bottom of the aquarium. How is the energy transferred to the gravel?

Exothermic,  physical change after it is already baked

Firstly, the water in the dams hold gravitational potential energy as they are above ground level. the gravitational potential energy is then transferred to kinetic energy as it falls, spinning the turbinethe turbine then spins the generator, which is a large magnet surrounded by metal coils. by doing this, the generator generates electricity. in this action, the energy transfer taken place is kinetic to electric energy