EAPS 105 EXAM WITH COMPLETE
SOLUTIONS 2025.
Chapter 2.4. Which type of heating is not considered primordial?
a. Accretional heating
b. Heating from planet forming collisions
c. Radiogenic heating
d. Core formation - ANSWER: C
Chapter 2.4.1. What is kinetic energy (motion) converted into when an asteroid collides with a
planet?
a. heat
b. potential energy
c. angular momentum
d. gravity - ANSWER: A
Chapter 2.4.1. Continuous bombardment of a planetary surface by many large asteroids would
have resulted in
a. large mountains.
b. a thick crust.
c. a magma ocean.
d. vaporization of the planet. - ANSWER: C
,Chapter 2.4.1. The ______ energy lost by the inward movement of nickel-iron within a
differentiating molten planetary body would be converted first into _______ energy and then into
______ energy.
a. momentum, thermal, gravitational
b. gravitational, kinetic, thermal
c. thermal, momentum, kinetic
d. kinetic, thermal, gravitational - ANSWER: B
Chapter 2.4.1. True/False: The Moon has lost most of its primordial heat. - ANSWER: True
Chapter 2.4.2. Which kind of heating results from the distortion of a planet's or moon's shape
due to gravitational interactions with another body?
a. accretional heating
b. tidal heating
c. core formation
d. radioactive decay - ANSWER: B
Chapter 2.4.2. Which of the following is a consequence of tidal interactions between the Earth
and the Moon?
a. The Earth's rotational rate is slowing
b. The Moon is moving farther away from the Earth
c. Deformation of the Earth's and Moon's crust and mantle
d. All of the above - ANSWER: D
Chapter 2.4.3., Box 2.7. If radioactive element X has experienced two half-lives since the
formation of the Earth (about 4600 Ma ago), how much X is remaining?
a. Twice as much since the formation of the Earth
b.
Half as much since the formation of the Earth
, c. A quarter as much since the formation of the Earth
d. An eight as much since the formation of the Earth - ANSWER: C
Chapter 2.4.3., Box 2.8. True/False: Larger planets conductively cool faster than smaller planets
- ANSWER: False
Chapter 2.4.4., Which of the following does not transfer heat from the interior of a planet to its
surface?
a. Conduction
b. Convection
c. Advection
d. Radiation - ANSWER: D
Chapter 2.4.3. Why did Lord Kelvin greatly underestimate the age of the Earth based on how
much it has cooled since its formation?
a. He neglected heat associated with radioactive decay
b. He neglected heat associated with core formation
c. He made a simple mathematical error that nobody caught for 50 years
d. He incorrectly assumed that the Earth started out completely melted - ANSWER: A
Chapter 2.4.4., Which planetary cooling process involves hot, buoyant, deep material rising up
through the cooler outer regions?
a. Conduction
b. Convection
c. Advection
d. Radiation - ANSWER: B
Chapter 2.4.5., Which is a consequence of plate recycling?
SOLUTIONS 2025.
Chapter 2.4. Which type of heating is not considered primordial?
a. Accretional heating
b. Heating from planet forming collisions
c. Radiogenic heating
d. Core formation - ANSWER: C
Chapter 2.4.1. What is kinetic energy (motion) converted into when an asteroid collides with a
planet?
a. heat
b. potential energy
c. angular momentum
d. gravity - ANSWER: A
Chapter 2.4.1. Continuous bombardment of a planetary surface by many large asteroids would
have resulted in
a. large mountains.
b. a thick crust.
c. a magma ocean.
d. vaporization of the planet. - ANSWER: C
,Chapter 2.4.1. The ______ energy lost by the inward movement of nickel-iron within a
differentiating molten planetary body would be converted first into _______ energy and then into
______ energy.
a. momentum, thermal, gravitational
b. gravitational, kinetic, thermal
c. thermal, momentum, kinetic
d. kinetic, thermal, gravitational - ANSWER: B
Chapter 2.4.1. True/False: The Moon has lost most of its primordial heat. - ANSWER: True
Chapter 2.4.2. Which kind of heating results from the distortion of a planet's or moon's shape
due to gravitational interactions with another body?
a. accretional heating
b. tidal heating
c. core formation
d. radioactive decay - ANSWER: B
Chapter 2.4.2. Which of the following is a consequence of tidal interactions between the Earth
and the Moon?
a. The Earth's rotational rate is slowing
b. The Moon is moving farther away from the Earth
c. Deformation of the Earth's and Moon's crust and mantle
d. All of the above - ANSWER: D
Chapter 2.4.3., Box 2.7. If radioactive element X has experienced two half-lives since the
formation of the Earth (about 4600 Ma ago), how much X is remaining?
a. Twice as much since the formation of the Earth
b.
Half as much since the formation of the Earth
, c. A quarter as much since the formation of the Earth
d. An eight as much since the formation of the Earth - ANSWER: C
Chapter 2.4.3., Box 2.8. True/False: Larger planets conductively cool faster than smaller planets
- ANSWER: False
Chapter 2.4.4., Which of the following does not transfer heat from the interior of a planet to its
surface?
a. Conduction
b. Convection
c. Advection
d. Radiation - ANSWER: D
Chapter 2.4.3. Why did Lord Kelvin greatly underestimate the age of the Earth based on how
much it has cooled since its formation?
a. He neglected heat associated with radioactive decay
b. He neglected heat associated with core formation
c. He made a simple mathematical error that nobody caught for 50 years
d. He incorrectly assumed that the Earth started out completely melted - ANSWER: A
Chapter 2.4.4., Which planetary cooling process involves hot, buoyant, deep material rising up
through the cooler outer regions?
a. Conduction
b. Convection
c. Advection
d. Radiation - ANSWER: B
Chapter 2.4.5., Which is a consequence of plate recycling?
