Respuesta :

Explanation:

[tex] \lambda = 8 \: m \\ T = 2 \: s \\ but \: f = \frac{1}{T} \\ f = \frac{1}{2} = 0.5 \: Hz \\ from \: wave \: equation \\ V = f \lambda \\ V = 8 \times 0.5 \\ V = 4 \: m {s}^{ - 1} [/tex]