Physics

Problem

A wave travelling on a stretched string is given by

y = 0.02\cos(0.8x - 40t + \dfrac{\pi}{6})

. Its speed of propagation is a)

40\,\text{m\,s}^{-1}

32\,\text{m\,s}^{-1}

50\,\text{m\,s}^{-1}

25\,\text{m\,s}^{-1}