Which of the following is an example of potential energy?

a bird positioned on the edge of a high cliff
a bike driving down the road
a dog eating dinner
a rock rolling on the ground through the air

Which statement best describes why an island's food web could be considered a closed system?

Energy flows freely into and out of the island's food web.
Energy enters and exits the system, matter does not.
New energy enters the food web, and matter is created as it moves through the web.
No energy exists outside the food web, only matter.

Question

Which of the following is an example of potential energy? 

a bird positioned on the edge of a high cliff 
a bike driving down the road 
a dog eating dinner 
a rock rolling on the ground through the air

	Which statement best describes why an island's food web could be considered a closed system?
 	
	Energy flows freely into and out of the island's food web.
	Energy enters and exits the system, matter does not.
	New energy enters the food web, and matter is created as it moves through the web.
	No energy exists outside the food web, only matter.

anonymous · Answer

a) The bird has a gravitational potential energy of mgh with respect to earth