During a lab investigation of Newton’s laws of motion, a student pulled a tablecloth out from under a beaker of water and a science book. Both items remained on the table after the tablecloth was removed.

Question

Which of these best explains why the beaker of water and science book stayed on the table instead of falling off the table when the tablecloth was removed?
Responses
A Moving the tablecloth applied an action force on the items and the items applied a reaction force on the table.Moving the tablecloth applied an action force on the items and the items applied a reaction force on the table.
B The tablecloth had less mass than the items, so a smaller force of gravity acted on the items.The tablecloth had less mass than the items, so a smaller force of gravity acted on the items.
C The acceleration of the items was equal and opposite to the acceleration of the tablecloth.The acceleration of the items was equal and opposite to the acceleration of the tablecloth.
D The items were at rest until the tablecloth was removed, so they tended to remain in the same location.

Answer 1

The best explanation for why the beaker of water and science book stayed on the table instead of falling off when the tablecloth was removed is:

D The items were at rest until the tablecloth was removed, so they tended to remain in the same location.

This is in line with Newton’s first law of motion, which states that an object at rest stays at rest unless acted upon by a net external force. When the tablecloth was pulled, the items did not experience a significant enough force to overcome their inertia and fall off the table.