Respuesta :

Answer;

 = 0.05 seconds

Explanation;

The speed of a wave is given by the product of frequency and wavelength;

Speed = Frequency × wavelength

Thus;

Frequency = speed/wavelength

                  = 200/10

                   =  20 Hz

But; period = 1/ frequency

Hence; Period = 1/20

                         = 0.05 seconds