A rock is dropped from a vertical cliff. The rock takes 3.00 s to ...

[javeds]

A rock is dropped from a vertical cliff. The rock takes 3.00 s to reach the ground below the cliff. A second rock is thrown vertically from the cliff. It takes 2.00 s to reach the ground below the cliff from the time it is released.
 
  With what velocity was the second rock released? A)
 
  4.76 m/s upward
  B)
 
  5.51 m/s downward
  C)
 
  12.3 m/s upward
  D)
 
  4.76 m/s downward
  E)
 
  12.3 m/s downward

Question 2

If the electric field is zero in some region of space is the electric potential zero there as well? Explain.
 
  What will be an ideal response?

[ergserg]

Answer to Question 1

E

Answer to Question 2

Not necessarily. The electric field is related to the rate of change of electric potential, not to the value of the electric potential. Therefore, if the electric field is zero in some region of space, it follows that the electric potential is constant in that region. The constant value of the electric potential may be zero, but it may also be positive or negative.