A toy car was used in an investigation about unbalanced forces. During which of the following scenarios was the car not experiencing an unbalanced force? * 20 points
1.The toy car speeds up as it rolls down a ramp.
2.The toy car travels forward at a constant speed.
3.The toy car slows down as it rolls up a hill.
4.The toy car changes direction at a constant speed.

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. which list best describes the forces on the piano in the proper order? a.positive force, balanced force, negative force b.negative force, balanced force, positive force c.positive force, unbalanced force, negative force d. negative force, unbalanced force, positive force