Chapter 2 - Acute Angles and Right Triangles - Section 2.5 Further Applications of Right Triangles - 2.5 Exercises - Page 90: 44c

As the speed limit increases, the amount of land that should be cleared also increases.

When the speed limit is 55 mph, the amount of land that should be cleared is $d = 23.4~ft$ When the speed limit is 65 mph, the amount of land that should be cleared is $d = 48.3~ft$ We can see that as the speed limit increases, the amount of land that should be cleared also increases.