Question

question:
when two objects with very different masses are attracted by gravity, the smaller-massed object will do most of the moving. why?

answer options:
select one of four
the larger object pushes with more force. the larger object has much more inertia.
the larger object needs a push. only large objects have gravity.

Explanation:

• Analyze each option:
• "The larger object pushes with more force": According to Newton's third law, the gravitational force between two objects is equal in magnitude (action - reaction pair), so this is wrong.
• "The larger object has much more inertia": Inertia is related to mass ($I\propto m$). A larger - massed object has more inertia, meaning it resists changes in its state of motion more. So the smaller - massed object, with less inertia, will move more. This is correct.
• "The larger object needs a push": Gravitational attraction is a force that acts without the need for an additional push. This is a wrong concept.
• "Only large objects have gravity": All objects with mass have gravity (Newton's law of universal gravitation $F = G\frac{m_1m_2}{r^2}$), so this is wrong.

Answer:

The larger object has much more inertia.