The maximum speed around a level curve is 30. mi/h. What is the maximum speed around a curve with twice the radius? (Assume all other factors remain unchanged.)
A) 120. mi/h
B) 42. mi/h
C) 21. mi/h
D) 60. mi/h
E) 45. mi/h

Question

Quizplus · Accepted Answer

The maximum speed around a curve is proportional to the square root of the radius. If the radius is doubled, the maximum speed increases by a factor of √2. Therefore, the new speed is 30 * √2 ≈ 42.4 mi/h, which rounds to 42 mi/h.

The Maximum Speed Around a Level Curve Is 30