Ontario Grade 9 Science Class Practice Exam

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Prepare for the Ontario Grade 9 Science Class Exam. Engage with interactive questions and detailed explanations to solidify your knowledge. Enhance your understanding of essential science concepts and boost your confidence for the test!

Each practice test/flash card set has 50 randomly selected questions from a bank of over 500. You'll get a new set of questions each time!

Practice this question and more.

What is retrograde motion?

A large cloud of dust and gas.
The movement of planets in a backward (westward) direction relative to the stars.
A small body moving in the solar system.
The mass of an atom.

The correct answer is: The movement of planets in a backward (westward) direction relative to the stars.

Retrograde motion refers specifically to the apparent backward (westward) movement of planets in the sky, as observed from Earth's perspective. It is a result of the differing orbital speeds and paths of Earth and the planets, and does not refer to a specific type of body or object like a cloud of dust and gas (A), small body (C), or the mass of an atom (D). Therefore, these options are incorrect in relation to the question about retrograde motion.