Understanding Nodes and Frequencies in a Uniform String Under Tension

Join the discussion
Registration is free. Ask a follow-up in this thread, or start your own.
1 reply · 5K views
tourjete
Messages
23
Reaction score
0

Homework Statement



A uniform string of length 2.5 m and mass 0.01 kg is placed under a tension of 10 N.

1. What is the frequency of the fundamental mode?

2. If the string is plucked and is then touched at a point 0.5 m from one end, creating a node, what frequencies persist?

Homework Equations



[tex]\omega[/tex] = [tex]\sqrt{T/\mu}[/tex]* n[tex]\pi[/tex]/L where [tex]\mu[/tex] = M/L

The Attempt at a Solution



I got the first part, I just plugged all the given information into the equation and used n=1 since it asked for the fundamental mode. I got 62.8319 radians/second.

I'm a bit lost as to what the concept of a node is. Do I just use the same equation again, but use L = 2.5 - .5 = 2 m? Or do I use n=5 since the string is now divided into fifths?
 
Physics news on Phys.org
Supposed the string is fixed at both ends, its length is equal to a half-wave in the fundamental mode. There is no motion at a node. Draw the standing wave when there is a node at 0.5 m from one end. Where are the other nodes?

ehild