 #1
vegbird
 1
 0
 Homework Statement:

Straight line AB connects two point sources that are 5.00 m
apart, emit 300 Hz sound waves of the same amplitude, and emit
exactly out of phase. (a) What is the shortest distance between the
midpoint of AB and a point on AB where the interfering waves
cause maximum oscillation of the air molecules? What are the
(b) second and (c) third shortest distances?
 Relevant Equations:
 This is from my physics textbook, the solutions are a) 0; (b) 0.572 m; (c) 1.14 m
However, I do not understand it at all. Since two point sources at A and B are exactly out of phase. The mid point is a node where the amplitude is zero with zero oscillation. How can part (a) be zero? Should that be a quarter of the wavelength away from the mid point?