Gravitational Potential Energy (Problem 19)

In Example 7.7, we found that the speed of a roller coaster that had descended 20.0 m was only slightly greater when it had an initial speed of 5.00 m/s than when it started from rest. This implies that $\text{Δ}{\text{PE >> KE}}_{\text{i}}$. Confirm this statement by taking the ratio of $\text{Δ}\text{PE}$ to ${\text{KE}}_{\text{i}}$. (Note that mass cancels.)