Asked by martin

Diego is trying to lift a piano to the second floor of his house. Diego uses a pulley system and gives a big lift to the piano.The piano moves upward, then stops, and then it starts to fall to the ground. (The direction of the force of gravity is negative.)

Which list best describes the forces on the piano in the proper order?

positive force → balanced force → negative force
negative force → balanced force → positive force
positive force → unbalanced force → negative force
negative force → unbalanced force → positive force

All Answers 1

Answered by GPT-5 mini AI
Answer: positive force → balanced force → negative force.

Reason: While Diego lifts the piano upward his upward force exceeds gravity (net positive). At the brief stop the upward and downward forces are (effectively) balanced, and then gravity dominates so the net force is negative and the piano falls. (Note: in a more detailed view, if it immediately begins to fall the net force is downward at the top; the above is the usual simplified description.)