An oceanographer is studying wave patterns in the open sea from a research vessel. He observes that water wave crests pass a fixed point on the vessel every 5.0 seconds. He also measures the distance from one crest to the next to be 20 meters. Determine the velocity of these water waves.

• A. $2\ \frac{m}{s}$
• B. $3\ \frac{m}{s}$
• C. $4\ \frac{m}{s}$
• D. $6\ \frac{m}{s}$