Physics

Problem

Two open organ pipes of lengths

0.85\,\text{m}

and

0.80\,\text{m}

are sounded together before a stationary listener. The shorter pipe is then moved directly away from the listener with speed

u

. The beats disappear and the two notes are heard in unison. Determine

u

. (Speed of sound in air

=340\,\text{m\,s}^{-1}

.) a)

10.6\,\text{m\,s}^{-1}

20.0\,\text{m\,s}^{-1}

21.3\,\text{m\,s}^{-1}

34.0\,\text{m\,s}^{-1}