Posted by confused on .
A woman is sitting in a boat at anchor on a lake. Her boat bobs up and down once every 2.0·s. She notices that when the front of her 3.0·m long boat is at one wave crest, a second crest is at the middle of her boat, and a third is at the end.
What is the frequency of the waves?

math 
Steve,
It doesn't matter how long her boat is. The boat bobs up and down every 2 seconds. In that time, two wave fronts have passed. So, the frequency is 2waves/2sec = 1/sec = 1 Hz.

math  my bad 
Steve,
Damon got it right.
The two wave fronts means that the boat has bobbed twice by the time they have passed, but it only bobs once in 2 seconds. So, frequency is indeed 1/2 Hz