# Homework Help: Wavelength of traveling wave on string (one end clamped and one end free)

1. Jul 26, 2015

### Dalip Saini

1. The problem statement, all variables and given/known data
A 30-cm long string, with one end clamped and the other free to move transversely, is vibrating in its second harmonic. The wavelength of the constituent traveling waves is
• A -- 10 cm

• B -- 40 cm

• C -- 120 cm

• D -- 30 cm

• E -- 60 cm

2. Relevant equations
for second harmonic n=2
(2L)/n= wavelength

3. The attempt at a solution
(2*30)/(2) = 30 cm
Put the answer is 40 cm, and I don't understand why

Last edited by a moderator: Jul 27, 2015
2. Jul 26, 2015

### ehild

The formula you used is wrong. Where are the nodes and antinodes of that vibrating spring?

3. Jul 27, 2015

### Orodruin

Staff Emeritus
To expand on ehild's answer, you have used the expression for a string where both ends are fixed (or both free). You need to correct forthe fact that your string is fixed in one end and free in the other. This goes for both your threads.