The transverse displacement of a string fixed at both ends is given by $y=0.6 \sin \left(\frac{2 \pi x}{3}\right) \cos (120 \pi t)$ where $x$ and $y$ are in metres and $t$ is in seconds. The length of the string is $1.5\, m$ and its mass is $3.0 \times 10^{-2} kg$. The tension in the string is equal to