Work is done by gravity on a bowling ball that rolls A) along ...

[rmenurse]

Work is done by gravity on a bowling ball that rolls
 
  A) along a horizontal surface.
  B) on a sloped surface.
  C) both of these
  D) none of the above

Question 2

Since natural gas creates carbon dioxide, why would it reduce global warming to switch from coal to natural gas?
 
  A) Actually, such a change would not reduce global warming.
  B) Because electricity from natural gas plants would cost more and thus it would be used less.
  C) Because mining is not needed in order to obtain natural gas.
  D) Because natural gas uses less carbon per joule of energy than does coal.
  E) Because natural gas plants produce a less polluting type of carbon dioxide.

[pikon]

Answer to Question 1

Answer: B

Answer to Question 2

D

[rmenurse]

Excellent

[marict]

Gracias!