Write the equation for the fundamental standing sound waves in a tube that is open at both ends. If the tube is `80 cm` long speed of wave is `330 m//s` . Represent the amplitude of the wave at an antinode by `A` .

Answer

A, B, C

Explanation

Fundamental frequency `= (nu)/(2l)`
`f = (330)/(2 xx 0.8)`
`f = 206.25 H_(Z)`
`omega = 2 pi f = 1297 rad//s`
`k = (omega)/(nu) = (1297)/(330) = 3.93 rad//s`
Now, `x = 0` (the open end) is an antiude . Hence, we can write the equation,
`y = A cos kx sin omegat`