Where does the energy in the ecosystem start?

Which best describes the difference between internal and thermal energy?

What surface does the epithelial tissue cover? a. the surface of the body b. lines internal organs c. forms many glands d. all of the above

Aball is rolled uphill a distance of 5 m before it slows, stops, and begins to roll back. the ball rolls downhill 9 m before coming to rest against a tree. what is the magnitude of the balls displacement? a. 4 meters b. 9 meters c. 14 meters d. 45 meters