The three principal sources of the internal heat of terrestrial planets are
A) accretion, differentiation, and eruption.
B) accretion, differentiation, and radioactivity.
C) convection, differentiation, and eruption.
D) conduction, convection, and eruption.
E) conduction, differentiation, and accretion.
Question 2
Which of the following statements correctly describes the law of conservation of energy?
A) Energy can change between many different forms, such as potential, kinetic, and thermal, but it is ultimately destroyed.
B) An object always has the same amount of energy.
C) The fact that you can fuse hydrogen into helium to produce energy means that helium can be turned into hydrogen to produce energy.
D) The total quantity of energy in the universe never changes.
E) It is not really possible for an object to gain or lose potential energy because energy cannot be destroyed.