Question

as a stunt, performers sometimes use a table, set with a tablecloth and dishes, and pull the tablecloth out from under the dishes. when performed correctly, the dishes on the table stay in place. which best explains why the dishes remain in place instead of being pulled off with the tablecloth? a the tablecloth applied an equal and opposite force onto the dishes. b the mass of the dishes is so great that they have no acceleration. c the dishes were at rest and remained at rest because no unbalanced forces acted upon them. d the velocity of the dishes increased.

Explanation:

This is an example of Newton's first - law of motion (inertia). Objects at rest tend to stay at rest unless acted upon by an unbalanced force. When the tablecloth is pulled quickly, the time of force application on the dishes is very short, and the frictional force is not sufficient to cause a significant change in their state of motion. Option A is incorrect as the tablecloth's force on the dishes is not enough to balance and keep them still in the way described. Option B is wrong because the mass of common dishes is not so great to completely prevent any acceleration due to a force. Option D is incorrect since the velocity of the dishes remains close to zero if the stunt is done correctly. Option C is correct as the dishes were initially at rest and remained at rest because the forces acting on them (mainly the small frictional force from the tablecloth) were not enough to move them.

Answer:

C. The dishes were at rest and remained at rest because no unbalanced forces acted upon them.