What two measurements of a wave do you need to calculate its speed?

Suppose you are watching water waves pass under the end of a pier. How can you figure out their frequency.

A wave has a speed of 3 m/s and a frequency of 6 wavelengths/s. What is its wavelengths.

Imaging you are on a boat in the middle of the sea. You are in charge of recording the properties of passing ocean waves into a ship's logbook. What types of information could you record? How would this information be useful? Explain your answer.

What are three properties of a wave that can be measures.

How is amplitude related to energy?

How are longitudinal waves measured?