Answer:
0.2 Hz
Explanation:
Frequency: This can be defined as the number of circles completed by a wave in one seconds. The s.i unit is hertz.
From the question,
If 4 Waves arrives on the shore every 20 seconds,
Then,
x waves will arrives on the shore in one seconds
Solving for x
x = (4×1)/20
x = 0.2 Hz
Hence the frequency of the wave is 0.2 Hz
