Question

Which example identifies a change in motion that produces acceleration?

Answer 1

Acceleration is the rate at which an object changes its velocity. It defines how much the velocity is changing. The acceleration can be negative and positive. Negative acceleration is when the object slows down, while positive while the object goes faster.
A ball moving at a constant speed around a circular track produces acceleration. 

Answer 2

A ball moving at a constant speed around a circular track produces acceleration.