# Homework Help: Finding freqency from 2 insturments playing together

1. Jul 4, 2011

### Patdon10

1. The problem statement, all variables and given/known data
You are playing a note that has a fundamental frequency of 420 Hz on a guitar string of length 49 cm. At the same time, your friend plays a fundamental note on an open organ pipe, and 6 beats per seconds are heard. The mass per unit length of the string is 2 g/m. Assume the velocity of sound is 343 m/s.

a. What are the possible frequencies of the open organ pipe? (Enter your answers from smallest to largest.)

b.When the guitar string is tightened, the beat frequency decreases. Find the original tension in the string.

c.What is the length of the organ pipe?

2. Relevant equations

3. The attempt at a solution

The book I'm using is pretty terrible, and shows almost no examples. I learn through examples, and I'm absolutely willing to try. This problem is from my last homework assignment (meaning it won't help my grade), I'd just like to learn how to do it. Can someone give me a nudge in the right direction?

2. Jul 4, 2011

### Patdon10

The answer for a is 418 hz and 422 hz