A travelling wave is described by the equation $$y(x, t) = 0.05\sin(8x - 4t)$$ m. The velocity of the wave is: [All the quantities are in SI unit]

The wave equation is given as: $$y(x, t) = 0.05\sin(8x - 4t)$$ m.

The standard form of a traveling wave is: $$y(x, t) = A \sin(kx - \omega t)$$, where:
- $$A$$ is the amplitude,
- $$k$$ is the wave number (in rad/m),
- $$\omega$$ is the angular frequency (in rad/s).

Comparing the given equation to the standard form:
- The coefficient of $$x$$ is $$k = 8$$ rad/m,
- The coefficient of $$t$$ is $$\omega = 4$$ rad/s.

The velocity $$v$$ of a wave is given by the formula:
$$v = \frac{\omega}{k}$$

Substituting the values:
$$v = \frac{4}{8} = 0.5$$ m/s.

Therefore, the velocity of the wave is 0.5 m/s.

The correct option is C. 0.5 m s$$^{-1}$$.