Approximately what percentage of the energy in one trophic level becomes incorporated into the next level?

Approximately 10% percent of the energy in one trophic level becomes incorporated into the next level.

See attachment for an illustration of the transfer of energy in trophic levels. 

The speed of  sound:   sound travels  at different speeds depending on what it istraveling through. of the three mediums (gas, liquid, and solid)  sound waves travel the slowest through  gases, faster  through  liquids, and fastest  through  solids.