Question

Choose the best explanation from among the following: A. It takes more energy to go from the Moon to the Earth because the Moon is orbiting the Earth. B. The escape speed of the Moon is less than that of the Earth; therefore, less energy is required to leave the Moon. C. The situation is symmetric, and hence the same amount of energy is required to travel in either direction.

Answer 1

Answer:

B. The escape speed of the Moon is less than that of the Earth; therefore, less energy is required to leave the Moon.

Explanation:

Since the speed required to escape from the gravitational attraction of the Moon is less than the speed required to escape from the gravitational attraction of the Earth, less energy is required to travel from the Moon to the Earth, than is required to travel from the Earth to the Moon. This is because the kinetic energy is directly proportional to the square of the velocity.