What is the Path Difference: Waves

[ixerr]

Homework Statement

Two in-phase speakers 4.50 m apart in a plane are emitting 1690 Hz sound waves into a room where the speed of sound is 343 m/s. Consider a point that is 8.50 m in front of one of the speakers, perpendicular to the plane of the speakers. What is the path difference (in wavelengths) between the two sound waves at this point?

Homework Equations

Hypotenuse Equation...

The Attempt at a Solution

Since the speakers are 4.50 m apart, and the point is perpendicular to one of the speakers, it essentially makes the shape of a triangle. I find the hypotenuse, which is 9.6178 m, and then subtract 8.50 m from it to find the path difference. But that answer is not right :( What should I be doing..?

 

[BruceW]

You've got the path difference in meters, but the question asks for the path difference in wavelengths. You're halfway there.