• Subject:

...

• Topic:

...

For the stationary wave $y=4\mathrm{sin}\text{\hspace{0.17em}}\left(\frac{\pi x}{15}\right)\mathrm{cos}\left(96\text{\hspace{0.17em}}\pi t\right)$, the distance between a node and the next antinode is

(1) 7.5

(2) 15

(3) 22.5

(4) 30