Question 26

Gravity causes the object's change in motion when a ball falls from a shelf to the floor.

In this scenario, gravity is the force that pulls the ball downward, resulting in its change in motion as it falls from a higher position to a lower one.

A) A person running from one end of a room to the other

In this case, the person's change in motion is primarily caused by their muscular force and not gravity. The person is actively propelling themselves forward, demonstrating that gravity plays a minimal role in this specific motion.

B) A ball rolling to a stop on the floor

While the ball does experience a change in motion, this is primarily due to friction between the ball and the floor, not gravity. Gravity is acting on the ball, but it does not directly cause it to roll to a stop; rather, it maintains the ball’s contact with the ground.

C) A bicycle turning when the rider moves the handlebars

The motion change in this scenario is due to the rider's steering input, which alters the direction of the bicycle. Gravity may influence the bicycle's stability, but it is not the primary force causing the change in motion during the turn.

D) A ball falling from a shelf to the floor

This scenario clearly illustrates gravity as the force responsible for the change in motion. The ball is subjected to gravitational pull, causing it to accelerate downward until it impacts the floor.

Conclusion

The correct answer is D, as gravity is the definitive force causing the ball's motion change when it falls. All other options involve different forces or factors that do not primarily relate to gravity's influence on motion, making them incorrect in this context.