Calculating Wave Velocity & Wavelength

Click For Summary

Homework Help Overview

The discussion revolves around calculating wave velocity and wavelength in the context of sound and standing waves. Participants are exploring the relationships between wave properties such as frequency, wavelength, and the behavior of particles in a medium.

Discussion Character

  • Exploratory, Conceptual clarification, Problem interpretation, Assumption checking

Approaches and Questions Raised

  • The original poster attempts to calculate the time it takes for a molecule in a sound wave to return to its normal position, using the wave's velocity and wavelength to find frequency and period. Another participant raises a similar problem regarding standing waves on a string, calculating wavelength but expressing uncertainty about the next steps. Questions arise about the distance between nodes and the relevance of the length of the string in this context.

Discussion Status

Participants are actively engaging with the problems, with some providing calculations and others questioning the assumptions made, particularly regarding the lack of a given length in the second problem. There is a mix of interpretations about how to approach the node spacing in standing waves.

Contextual Notes

Some participants note the absence of specific information, such as the length of the string in the standing wave problem, which may affect their calculations and understanding of the problem.

timtng
Messages
25
Reaction score
0
A sound wave of velocity 600 m/s has a wavelength of 3 m. At a certain instant one of the molecules of the medium is at its normal position. How long will it be before this same molecule is again at its normal position?

v=fλ, f=v/λ =(600m/s)/3m = 200Hz
T=1/f=1/200=.005s

t=T/2 = .0025s Is this answer correct?

Thanks
 
Physics news on Phys.org
Another problem of the same sort.

Standing waves are produced on a string for which the velocity of transverse waves is 200 m/s. The frequency of vibration is 500 Hz. How far apart are the nodes?

I can only find λ, λ=v/f=200/500=.4m

I don't know how to finish the rest of the problem
 
So the answer should be λ/2?
 
shouldn't the answer be: L-λ/2
 
I figured since they ask how far apart are the nodes, L has to be a contributing factor.
 
I figured since they ask how far apart are the nodes, L has to be a contributing factor.

Did you notice that there was no "L" given in the problem?

We were given, instead, the frequency.

If you were given the wavespeed (determined by the mass and tension of the string) and length, then you could find the frequency. Here, that's not necessary.
 

Similar threads

  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 13 ·
Replies
13
Views
1K
  • · Replies 10 ·
Replies
10
Views
2K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 6 ·
Replies
6
Views
2K
Replies
3
Views
1K
  • · Replies 15 ·
Replies
15
Views
3K
Replies
5
Views
3K
  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 4 ·
Replies
4
Views
4K