The most underlying feature of machines is A) energy ...

[bobthebuilder]

The most underlying feature of machines is
 
  A) energy conservation.
  B) that energy input always equals energy output.
  C) that power input always equals power output.
  D) all of the above
  E) none of the above

Question 2

As the moon circles Earth, the net force on it is
 
  A) backward.
  B) directed outward away from Earth.
  C) directed inward toward Earth.
  D) forward.
  E) zero.

[Jayson]

Answer to Question 1

Answer: A

Answer to Question 2

C

[bobthebuilder]

Gracias!

[duy1981999]

Excellent