pre cal please help me i'm totally lost =[?

Question

Can u please answer me this question.
Thanks

An earthquake occurred at 9:40 A.M. on Nov. 1 1755 at Lisbon, Portugal, and it started a tsunami ( Often called a tidal wave) . It produced waves that traveled more than 540 ft/sec ( 370mph) and reached a height of 60 ft. If the period of the waves was 30 min or 1800 sec, estimate the length L between the crests.

Answer 1

The waves travel at 370 mph and there is a new one every half hour (every 30 minutes).

Therefore in half an hour a wave travels

370/2 = 185 miles

So the waves are spaced 185 miles apart crest to crest.

Answer 2

wow...