Final answer:
The isolated system for which momentum is conserved in this scenario is the ball and the earth. When the ball is released and falls toward the ground, the Earth also experiences an immeasurably small change in momentum due to the force of the ball.
Step-by-step explanation:
The isolated system for which momentum is conserved in this scenario is the ball and the earth.
When the ball is released and falls toward the ground, the Earth also experiences an immeasurably small change in momentum due to the force of the ball. While the effect on the Earth is negligible compared to the ball, it is still a part of the overall momentum-conserving system. In the absence of external forces, like air resistance, the law of conservation of momentum dictates that the total momentum of an isolated system remains constant. The isolated system in this scenario comprises both the ball and the Earth, making the correct answer 3) the ball and the Earth.
As the ball falls, Earth experiences an equal and opposite reaction due to Newton's third law of motion. The momentum gained by the falling ball is exactly canceled out by an equal and opposite momentum gained by the Earth. Therefore, the combined momentum of the ball-Earth system remains constant. This concept is rooted in the conservation of angular momentum and the principle of action and reaction.
While it might be tempting to consider only the ball or the Earth individually, the conservation of momentum emphasizes that it is the total momentum of the entire system that remains unchanged in the absence of external forces, making 3) the ball and the Earth the accurate choice.