Which of the following correctly describes how the process of gravitational contraction can make a star hot?
A) When a star contracts in size, gravitational potential energy is converted to thermal energy.
B) Gravitational contraction involves nuclear fusion, which generates a lot of heat.
C) Heat is generated when gravity contracts because gravity is an inverse square law force.
D) Gravitational contraction involves the generation of heat by chemical reactions, much like the burning of coal.

Question

Quizplus · Accepted Answer

As a star contracts, gravitational potential energy is converted into thermal energy. This is because the particles in the star are getting closer together, which causes them to heat up due to the increased kinetic energy of their movement.

Answer: B, C, D are incorrect
 Gravitational contraction does not involve nuclear fusion (option B); this only occurs in the core of stars when they have already formed. Gravity is an inverse square law force, but this does not explain how it generates heat (option C). Finally, chemical reactions are not involved in gravitational contraction, so option D is also incorrect.

Which of the Following Correctly Describes How the Process of Gravitational