Solve the given parts of following problem:
Problem: Ocean waves move toward the beach with a speed of 8.90 m/s and a crest-to-crest separation of 15.0 m. You are in a small boat anchored off shore.
Part A: At what frequency do the wave crests reach your boat?
Part B: You now lift anchor and head out to sea at a speed of 15 m/s. At what frequency do the wave crests reach your boat now?
I need help to find at what frequency the wave crests reach your boat now.