Answer
Four.
Work Step by Step
We can find the required antinodes as follows:
$f_n=\frac{nv}{2L}$
$\implies n=\frac{2f_nL}{v}$
We plug in the known values to obtain:
$n=\frac{2(603)(1.33)}{402}=4$
You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.