Suppose the main water pipe breaks in a nuclear power plant, ...

[genevieve1028]

Suppose the main water pipe breaks in a nuclear power plant, shutting off the water flow. If the control rods fall immediately into place, stopping the chain reaction, is there still a problem?
 
  A) Yes, because radioactivity continues to create lots of thermal energy.
  B) Yes, because the uranium can still fission even though it is not chain-reacting.
  C) Yes, because the control rods stop only the fissioning of uranium and not the fissioning of plutonium.
  D) No, because no heat can be created once the fission reaction is shut off.
  E) No, because the small amount of heat that continues being created is not enough to cause any danger.

Question 2

A heavy rock and a light rock are dropped from the same height. The forces exerted on them by air are negligible. Which of the following statements about these rocks are correct? (There could be more than one correct choice.)
 
  A) Both rocks have the same kinetic energy when they reach the ground.
  B) Both rocks have the same speed when they reach the ground.
  C) The heavier rock reaches the ground before the lighter rock.
  D) Just as they were released, the two systems consisting of each rock and Earth had the same amount of gravitational potential energy.
  E) When they reach the ground, the heavier rock has more kinetic energy than the lighter rock.

[l.stuut]

Answer to Question 1

A

Answer to Question 2

B, E