Final answer:
In the movie 'Up,' Carl Fredrickson's life changed due to the loss of his beloved wife, Ellie. This event motivated him to fulfill their lifelong dream of traveling to Paradise Falls.
Step-by-step explanation:
In the movie 'Up,' Carl Fredrickson's life changed due to an internal force when he experienced the loss of his beloved wife, Ellie. This event had a significant impact on Carl's emotional well-being and shaped his outlook on life. It motivated him to fulfill the lifelong dream that he and Ellie had of traveling to Paradise Falls by attaching countless balloons to his house and embarking on a journey filled with adventure and self-discovery.