Respuesta :

mathematically,

[tex]frequency = \frac{1}{t} [/tex]

where t = time

from the question, t= 0.077sec

substitute it in the formula

[tex]frequency = \frac{1}{0.077} [/tex]

[tex]frequency = 12.987 {s}^{ - 1} [/tex]

approximately 13s^-1