# Ripple Tank questions

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1. Jan 12, 2015

### Quantum Fizzics

1. The problem statement, all variables and given/known data
Two sources 6.0 cm apart, operating in phase, produce water waves. A student selects a point on the first nodal line and measures from it 30.0cm to a point midway between the sources and 5.0cm (on the perpendicular) to the right bisector.
a) what is the wavelength

2. Relevant equations
PS1 - PS2 = (n-1/2)lambda
lambda = xnd/L(n-1/2)

3. The attempt at a solution
I have tried to use both of these equations, & I still can't get the answer I don't understand.. the answer is 2.0cm and the answers I've been getting are 11.7cm, 60cm, 20cm... I dont understand

2. Jan 12, 2015

### Bystander

Try giving us a few definitions: first nodal line; right bisector; perpendicular to the right bisector. Been a while since I played with a ripple tank, and I'm not remembering what some of the descriptive terms mean.

3. Jan 12, 2015

### haruspex

Seems to me you need to be told it's the first point on the first antinodal line.
Maybe you've derived the wrong diagram. In Cartesian coordinates, if the sources are at (-3,0) and (+3,0), and we take the first node on the first nodal line in the first quadrant, where do you think the chosen node is?