1. The problem statement, all variables and given/known data A double-slit interference experiment is done in a ripple tank (a water tank using a vibrating rod to produce a plane wave on the surface of the water). The slits are 6.00 cm apart, and a viewing screen is 2.15 m from the slits. The wave speed of the ripples in water is 0.012 m/s, and the frequency of the rod producing the ripples is 5.20 Hz. How far from the centerline of the screen will a second order minimum be found? The second order minimum is the second time that destructive interference happens. 2. Relevant equations Y = (m + 1/2)(λ*R/d) λ= v/f 3. The attempt at a solution Y = (2 + .5) * ((.012*2.15)/(5.2*.06)) = 2.06E-1 m If I'm understanding this equation correctly, Y = distance from central fringe. M = xth order minimum/maximum. R= distance from slits to screen. d= distance between slits. I'm doing something wrong though, somehow! Thanks for the help.