an oboe plays A (440 Hz) at 20degrees Celsius. at the same time, an identical oboe plays the same note at 0degrees, and beats are heard. what is the beat frequency ?

Question

jamesj · Answer

Nice question.  
$$ v = \lambda f $$
f is the same for the two notes.  So what's different?

anonymous · Answer

would $$\lambda$$  be whats different ?

jamesj · Answer

yes, it must be.  Now why?  Because v is different.  Why?  Because the speed of sound depends on the temperature of the air.