Determine the change in path length

[Matthew M]

Homework Statement

A ripple tank is setup and a point selected on the second nodal line. determine the change in path length from two wave sources if they are in phase and separated by 2cm and the wave length is 5cm

Homework Equations

not really sure of what equations to use?

The Attempt at a Solution

Dont understand what this question means?

 

[haruspex]

If you have quoted the question exactly (and there is no diagram) then I agree it's hard to decipher.
But my guess is they are asking for the difference in path lengths from two sources to a point P, given that:
- the sources are in phase and 2cm apart,
- the wavelength from each source is 5cm
- P is on the second nodal line of the interference pattern

 

[IAN 25]

A node occurs when two waves meet with a wavelength difference of nλ/2 where n is odd. The second nodal line means n = 3. Does this help.