Final answer:
Ernesto's rate of change of speed is the highest when he comes to a complete stop. Coming to a full stop means that his speed changes from a certain value to zero, representing the maximum deceleration.
Step-by-step explanation:
Ernesto's speed is changing when he either slows down or comes to a complete stop. From the information provided, we are asked if Ernesto's speed changes faster when he slows down or when he comes to a complete stop. The concept of acceleration includes slowing down (deceleration), speeding up, or changing direction. In this context, coming to a complete stop represents a change in speed from whatever value it was before to zero. Therefore, this is a form of acceleration (deceleration, to be specific).
When answering this question, the phrase 'changing faster' refers to a higher rate of deceleration. Coming to a complete stop means Ernesto's speed reduces to zero, which is the maximum rate of deceleration, assuming this happens in a finite time. Therefore, Option 2: Complete stop would be the point at which Ernesto's rate of change of speed is the highest because his speed reaches zero, compared to just slowing down, where his speed reduces but does not necessarily reach zero.