The Moons of Mars,Phobos (Fear)and Deimos (Terror),are Very Close to the Planet

question 16

Multiple Choice

The moons of Mars,Phobos (Fear) and Deimos (Terror) ,are very close to the planet compared to Earth's Moon.Their orbital radii are 9,378 km and 23,459 km respectively.What is the ratio of the period of revolution of Phobos to that of Deimos?

• A) 0.2528
• B) 0.3998
• C) 1.582
• D) 2.858
• E) 3.956

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Definitions:

Reciprocity Norm

The reciprocity norm is a social norm that expects individuals to respond to each other in kind, returning benefits for benefits received.

Favor

An act of kindness beyond what is usual or expected, often involving giving someone an advantage or showing support.

Past

The period of time or a segment of history that has already occurred, distinguished from the present and future.

Social-Responsibility Norm

A societal expectation that people will help those who are dependent upon them or in need of assistance.