A car driving along a highway at a speed of 23 m/s strays onto the shoulder. Evenly spaced parallel grooves called “rumble strips” are carved into the pavement of the shoulder. Rolling over the rumble strips causes the car's wheels to oscillate up and down at a frequency of 82 Hz. How far apart are the centers of adjacent rumble-strip grooves?

Answer 1

v = fλ
23 m/s = 84Hz * λ
λ = 23/84
λ = 0.2738095238 meters apart

Answer 2

v = fλ
23 m/s = 84Hz * λ
λ = 23/82
λ = 0.28048780498 meters apart

Answer 3

v = fλ
23 m/s = 82Hz * λ
λ = 23/82
λ = 0.28048780498 meters apart

This one is correct

Answer 4

23/82 m is correct