Physics

Problem

A stationary wave on a stretched string is given by

y=2A\sin\bigl(\tfrac{\pi x}{0.30}\bigr)\cos(120\pi t)

(SI units). Which one of the following positions

x

is always a node? a)

0.15\,\text{m}

0.45\,\text{m}

0.30\,\text{m}

0.20\,\text{m}