Speed of a Wave

  • Thread starter pmd28
  • Start date
  • #1
64
0

Homework Statement


A person fishing from a pier observes that five wave crests pass by in 7.4 s and estimates the distance between two successive crests to be 4.6 m. The timing starts with the first crest and ends with the fifth. What is the speed of the wave?



Homework Equations


f=1/T
v=λf

The Attempt at a Solution


I solved for the period first, so in 7.4 sec there was 5 waves. T=1.48
f=1/T=.6757
v=λf=4.6*(.6757)=3.11 m/s

I know my error has to do wit that sentence, "The timing starts with the first crest and ends with the fifth," but I'm not sure what I'm doing wrong.
 

Answers and Replies

  • #2
TSny
Homework Helper
Gold Member
13,186
3,496
Draw a sketch of a wave and number the crests 1 through 5. How many wavelengths are contained between 1 and 5?
 
  • #3
64
0
There are 4 wavelengths.
 
  • #4
TSny
Homework Helper
Gold Member
13,186
3,496
Good. So what should the period T actually be?
 

Related Threads on Speed of a Wave

  • Last Post
Replies
5
Views
2K
  • Last Post
Replies
3
Views
2K
  • Last Post
Replies
6
Views
2K
  • Last Post
Replies
7
Views
2K
  • Last Post
Replies
3
Views
2K
  • Last Post
Replies
3
Views
287
  • Last Post
Replies
8
Views
18K
  • Last Post
Replies
7
Views
3K
  • Last Post
Replies
1
Views
7K
Top